we'll be back at 6:00. on this sunday night, high stakes. team obama unleashes a full-court press on the road to the convention. tonight chuck todd and andrea mitchell on what the president needs to do. new evacuations in the gulf. the storm is gone but tonight the danger isn't over. deadly summer in one of america's biggest cities. how residents are fighting to take back the streets. they're going for gold once again tonight in london with kate middleton there cheering them on. and in the doghouse. good dogs, bad behavior and pet owners around the world adding their canine criminals to the lineup. captions paid for by nbc-universal television

from nbc news world head quarters in new york, this is "nbc nightly news" with lester holt. good evening. president obama is on the campaign trail tonight hitting states that are sure to be hotly contested and sharpening the attacks and talking points that are likely to frame this week's democratic convention in charlotte. that will include the charge that mitt romney and republicans are pushing failed economic policies of the past. as democrats prepare to take center stage they'll face the challenge of convincing undecided voters that the president's policies are healing a sick economy. it's a debate that was on full display and our white house correspondent kristen welker begins our coverage from boulder, colorado tonight. >> reporter: good evening. in 2008 president obama became the first democrat to win colorado in 16 years. now that winning coalition isn't as strong so he is aiming to get women and young voters like the ones on this college campus to turn out in force.

>> hey, guys. hello everybody. >> reporter: in boulder, president obama took his case to voters one by one at a local restaurant and later told a crowd of about 13,000 -- >> this is a region settled by people who understand we are not looking back, we are going forward. >> reporter: as delegates and protesters began to gather in charlotte ahead of the democratic national convention, president obama supporters spent their sunday morning trying to plug any bounce they got from the convention last weeks. >> it was a week of personal attacks, empty platitudes. the one thing you were left with is they think lying is a virtue. >> people want to know about the first term. very simple. general motors is alive and well and osama bin laden is not. >> reporter: vice president joe biden said the gop nominee is not ready to lead on foreign policy. >> he implied by the speech that he is ready to go to war in syria and iran. >> reporter: biden failed to

offer specifics while republicans tried to keep the focus on the economy. >> the biggest event won't be the speech thursday but the friday morning jobs report. >> reporter: top romney aide fired back on criticism that romney didn't mention afghan in the speech. >> the day before the convention speech governor romney traveled to indianapolis on wednesday and gave a speech before the american legion. >> reporter: off the campaign trail in new hampshire governor romney went to church near his home and began preparing for the upcoming debates. and this weekend his running mate, paul ryan got caught in the kind of slip of the tongue that has in the past tripped of joe biden and al gore with ryan telling a radio host he once ran a marathon in under three hours. in reality it took him much longer than that. ryan quickly owned up to the mistake. and for the first time president obama is weighing in on clint

eastwood's convention speech. telling "usa today" he's not easily offended. he calls eastwood a great actor. in the meantime campaign aides tell me president obama is working on his own convention speech on the sidelines. >> kristen welker, thanks. on the trail in boulder, colorado tonight. we want to bring in two more members of our nbc news political team, chuck todd and andrea mitchell who join us on the site of the democratic national convention. chuck, let me start with you. the democrats have had a chance to kind of review what happened in tampa with the republicans. how are they feeling now? >> reporter: there is a spring in their step. they are awfully confident bordering on cocky, if you will, about the position they are in and what they feel is the things romney wasn't able to accomplish at his convention. the big thing that romney was able to accomplish that even team obama will acknowledge is he fixed the likability issue. got people to know him personally. the fact that he needed to do that at his convention as far as

the obama campaign is concerned was a victory to them. that said, it doesn't mean it is easy going forward. it is amazing how confident they are going into their convention about where they would be. they thought they would be in a much worse place. >> andrea, it would be hard for the obama team to match the excitement generated four years ago. is there some fear that romney's suggestion that there might be disappointment among obama voters? suggestion that that might have hit a nerve. >> reporter: it might have hit a nerve and some democrats worry that the obama campaign can be too confident. they have to win a state like this one, north carolina. the president only won this by 14,000 votes last time. right now he and mitt romney are tied. they need to drive up the women's vote. the unemployment rate in north carolina is 9.6%. the romney forces are outspending the obama teams by two to one here. and perhaps it is best captured by a woman who came to me a couple of days ago. she approached me and said what

do you think about all of this. i asked her what she thought. she said my late husband is a republican. i voted for obama. i was leaning towards mitt romney because i'm worried about this economy, but now i'm really worried about the republicans, her words, pushing down on the glass ceiling. president obama needs to persuade that woman this week. >> andrea mitchell and chuck todd, thanks. >> our primetime coverage of the democratic national convention starts tuesday night at 10:00 eastern, 7:00 pacific on this nbc station. we turn to the aftermath of hurricane isaac along the northern gulf. there are new questions tonight about whether the new multibillion-dollar levee system that did such a good job protecting new orleans may have contributed to some of the flooding outside the city. gave gutierrez has our report. >> reporter: in st. tammany parish the pearl river is rising and officials are considering whether to evacuate 5,000 homes before it crests tomorrow.

>> we don't do this lightly because we don't want people out of their homes. we know what trouble it causes and concerns. but safety is first. >> reporter: gerald williamson has seen this before. during katrina his home had six feet of water. >> when you live by the water sometimes you live in the water. >> reporter: today in plaquemines parish flood victims apply for federal aid. >> i think you are going to have to build a wall to protect it and that is never going to happen. >> reporter: as flood waters drop and power crews work neighbors here are raising questions. >> it makes me angry because you are going to put this flood system up which is a good thing. it's a good thing. it stopped the city from flooding. it's a good thing. but you are not going to worry about where you are pushing the water. >> reporter: that speculation is stroj strongest in towns closer

to new orleans like la place, lafite and slidell. facing pressure from local officials the army corps of engineers says it will investigate whether new orleans $10 billion upgrades to the flood protection system came at the expense of surrounding communities. critics say it pushed more water to new places. >> there's lots of flooding out there. >> reporter: the army corps says it expects to find any impact minimal. >> we would not have built a system that would have induced flooding in other places. >> reporter: the upgraded system behind me was largely reinforcements and not new construction. and the army corps says that isaac was stronger than katrina and hung around longer. meanwhile 250,000 homes and businesses in the gulf coast are still without power. lester? >> gave gutierrez, thanks. now to a growing health alert. the spread of west nile virus cases in every one of the lower 48 states, what could be the worst west nile outbreak ever

recorded. the spraying continued from texas to georgia to new york. the cdc is worried about what is lingering in all that standing water down in the gulf after isaac. our report from chief medical editor dr. nancy snyderman. >> reporter: the cdc's latest numbers indicated it could be the worst year for the west nile virus since it was detected in the united states. >> it was introduced in 1999 and spread over a series of years through the bird population and got into the mosquitoes and the mosquitos bit people. >> reporter: the number of cases this year is sky rocketing. nearly 1,600 infections reported and 66 deaths, up 40% in one week. >> it is a late summer disease. the fact that we have so many cases this early and so

widespread does not bode well. >> reporter: every state except alaska and hawaii has seen outbreaks and nearly 70% of the cases come from six states, the hardest hit, texas with nearly half of the infections. health officials are launching efforts to prevent the spread of the potentially dangerous disease. from the air to the ground people are on patrol distributing flyers with preventive information and symptoms which tend to be mild in 80% of the cases. in 20% fevers, headaches and body aches and most worrisome for people over 70 are with weakened immune systems. west nile virus is a known threat for animals. while there is a vaccine for horses there is no vaccine yet for human beings, but there are increased calls to speed up development. experts recommend dressing in long sleeves and pants, staying indoors at dusk and dawn and using deet bug repellent. and draining pools or puddles of warm water which are breeding grounds for infected mosquitos. as people cleaning up after hurricane isaac, the cdc is on alert. it is offering to help states hardest hit by flooding to prevent potential uptick in

cases. dr. nancy snyderman, nbc news, new york. overseas tonight, a big headline from the war in afghanistan. u.s. forces have halted training of some afghan police for at least a month after a rash of insider attacks. members of afghan security forces have killed dozens of coalition troops this year, at least 12 in august alone. for insight on what this means for the mission there, i'm joined by nbc military analyst jack jacobs. colonel, doesn't this undermine the whole basis, the rationale for the american mission there? >> i think it does. if our mission is to train the afghans so that they can defend themselves then this halt touted by the government as being only a temporary halt and only for some units, really does undermine our mission. if we are to train the afghans then stopping training now makes it appear that we are through

with that mission. >> the focus here seems to be on afghan police in particular. why is this trouble so pronounced with police? >> the police are corrupt by and large, very poorly trained and very difficult to train. don't forget this is a country that relies almost exclusively on local control. local tribal control. and trying to influence what happens locally with national police has been extremely difficult. i think it's a mission that would take much longer than we have the political will to complete. >> thank you. >> you're welcome. >> in syria today, there was a pair of bombings right in the heart of damascus. several army officers were wounded in the blast. unicef says 1,600 people were killed in the last week making it the deadliest week yet in the ongoing civil war. from south korea tonight, news that the reverend sun myung moon, the self-proclaimed

messiah and founder of the unification church has died. the controversial church gained international fame in the 1970s and '80s. moon holding mass weddings, thousands of couples at a time. his church grew into a multibillion-dollar business empire while accused of duping followers out of money. sun myung moon was 92 years old. still ahead a deadly summer on the streets of america's second city. a lot of people wondering what is going on in chicago and what is being done to stop it. later, they are in the doghouse. their bad deeds on display making for a lot of laughs.

we're back with a closer look at what has been a violent summer on the streets of chicago.

55 homicides in august alone making it the deadliest month so far this year. this morning chicagoans woke up to news of at least ten more people shot, two more of them killed. what is being done to combat the crime? here is nbc's ron allen. >> reporter: in a chicago neighborhood that endured a long, hot, violent summer, a small band of residents holds another rally for peace. a deadly season that saw the murder of 7-year-old heaven sutton, shot in the back. august the deadliest month yet. this pastor leading the rally has been imploring his neighbors to help save what many fear has become a lost generation. >> it is a state of emergency. this is the civil rights issue of our day and time.

>> reporter: a local newspaper publishes the names. many of them young black men killed in their teens and 20s. often gang members, police say, locked in a drug trade that creates jobs and where disputes and petty ones are solved with easily accessible guns. some of the victims are by standers like jermaine winfield left paralyzed by his wounds, shot in three separate incidents during the past four years even after being confined to a wheelchair. >> if we don't make a stand now there will not be kids left to make a stand for. >> reporter: police claim they made progress by targeting districts in the city, and overall, crime is down and most of the violence happens in a few specific areas. during one spree at least 82 people were killed or wounded on the streets of chicago. last week the mayor with federal help stepped up the strategy of putting more police in the city's most violent areas and this morning the mayor

acknowledged the problem on "meet the press." >> we are making efforts to reduce the gang conflicts. it's gang-on-gang issues. it does not affect the whole city but anywhere it happens we will be dealing with it. >> reporter: in pastor acry's neighborhood, residents say it is the gangs increasing their fire power. >> we are the first down and the last to fight back. we have to fight back. >> reporter: he prays the young voices in his youth choir will survive to sing for many more summer seasons to come. ron allen, nbc news, chicago. when we come back here tonight, they are going for gold once again tonight in london.

those two weeks in london making her mark as one of team gb's biggest fans and kate middleton continues to dazzle, handing out medals tonight at the men's discus event at the paralympics.

one of the favorites for gold this week is american sprinter blake leiper. he made his mark as one of the fastest men ever. we get more on his story tonight from miguel el almaguere. >> reporter: in the world of track and field blake leaper is a rookie. an olympic sprinter who has only been running for three years. >> every time i step on the tracks i'm there to prove to them and to myself that i have accomplished something great. >> reporter: in london this weekend he is going for gold. at 22 his rise is one of the most elite runners in the world has come quickly but wasn't easy. few know what it is like to stand in his shoes. leaper was born without legs, a birth defect that set him apart but never slowed him down. >> at birth, the doctors told me i would never walk.

to be here running for my country around the world, i have no reason to feel sorry for myself. >> reporter: out of the blocks the olympian always set the bar high. in high school he defied the odds competing in two sports. after being fitted with new prosthetics he made strides as never before. in july he tied the world record in the 100 meters, 10.91 seconds. his coach, 1984 olympian and gold medalist, joaquin cruz. >> this is a kid that not long ago was not able to run at all. on the track he was not a runner. they gave him a set of legs. two and a half years later he is breaking a world record. >> reporter: with one world record under his belt blake isn't nearly done. he is closing in on a second world record, this one in the 200 meters. it's his favorite event. >> everybody in life has a challenge.

i think about all the things i have experienced in my life and times i have been laughed at and kids made fun of me. i let it all go and leave it on the track. >> reporter: a quest for gold from a young man who has proven he has the heart of a champion. nbc news, california. and we can report that blake leaper took bronze in the 200 meters. and a big upset in that race. oscar pistorius took silver. beating out at the finish out by brazil's allen olivier. when we come back good dogs behaving badly and getting called on it. h. e. . c. a. r. p. e. t.

finally tonight, what began with a few photos of good dogs gone bad has exploded into a full-lown internet sensations. pet owners adding their canine criminals to the lineup. here is nbc's anne thompson. >> reporter: it's puppy play group. they get to know each other. socialization skills that may keep these three from the dog shaming tumbling page. this internet sensation features

mug shots of the charming criminals and their rap sheets. this one hid food in the couch. this one steals money and this one blames the cat for its cat nip and cat toy addiction. the offenders are sure to bring a laugh as long as it is not your dog. >> a twist of humor. on some of the more frustrating aspects of being a dog owner sometimes. >> reporter: the web has long been good for that. take this video about an english mastiff. >> this is what i come home to. trash has been gone through. >> reporter: it has gotten almost 2.5 million hits. >> we have zeena. what about tank? i wonder if tank had anything to do with it? do you know about the trash? >> reporter: kim's four dogs are on facebook. >> we track the hits and the number of likes goes through the roof when the dogs are involved. >> reporter: why not? meet george. just the sweetest little thing until i bring out his harness

and leash and try to put them on him. really? every other time he runs and hides under the bed but not once in many, many takes. you have never let me put this on you, did he do that. is the problem the four legged creature or the two legged creature? >> the problem is probably always the two legged creature because i really see -- i mean, there is problem behavior but they are just being dogs. >> reporter: as mike demonstrates, they can be trained. >> sit. yes. >> reporter: but dog shaming may have already jumped the shark. >> i got an e-mail from my mother saying have you been on this site. i was surprised. it usually takes her a good six to eight weeks of something going viral for her to send it to me. >> reporter: as the world clicks on to see who is in the virtual doghouse. anne thompson, nbc news, new york. >> as all of us pet owners nod with full understanding. that is "nbc nightly news" for this sunday.