on the broadcast tonight, why now? in a tight economy with so many americans living on the financial edge, why are they being asked to pay so much more for gas? the iran threat. with the tension already high, tonight we're on a u.s. navy carrier in the thick of it, making its way through a critical route for oil. would you believe allergy season in february? depending on where you live, there's flowers in bloom and pollen in the air where it's supposed to be the dead of winter. and true love on this valentine's day. the landmark couple who changed a lot for a lot of other couples in america. a lot for a lot of other couples in america. "nightly news" begins now. captions paid for by nbc-universal television

good evening. with americans right now looking for any positive uptick in the economy, any reason to feel good about hiring or wages or industrial production, there's still one thing that could crush it all and ruin any hope for a real recovery right now, and that's the price of gas. too much of our economy runs on it, too many families depend on it, and very few people can afford to pay even more for it right now. the problem is gas prices are going up according to aaa, the national average for regular unleaded is up 13 cents in just the last month, averaging $3.51 a gallon across the country. and that's continuing the climb from last month, when we saw the highest gas prices on record for the month of january. nbc's john yang starts us off tonight on why and what more we can expect.

>> reporter: from here in chicago -- >> everything is going up. except the paychecks. >> -- to charlotte, north carolina -- >> it trickles down. you have less money for everything else. >> -- to los angeles. >> it might be time to invest in a bicycle. >> -- americans are feeling a big pain in the pump that's spreading to the rest of their lives. >> i can't spend my money like i want to. i've got to really budget it. >> and it's not just family finances being squeezed. analysts say every 50 cent increase in gas prices takes almost $150 billion out of the rest of the economy. that's bad news during a struggling recovery. it's changed the way that frank's famous frank's famous kitchen and bakery in glendale, california, does business. they're more careful about how they use the delivery truck. >> you can't deliver two sandwiches five miles away. it doesn't sound like a lot, but it adds up quick. >> reporter: that's because los angeles gas prices, already among the highest in the nation, jumped 15 cents in just the last month.

>> at those prices, we're dumping $120 in the tank every three to four days. why the price spike? according to experts, it's a combination of rising tensions in the middle east, big east coast refineries shutting down, and increased demand for gas in china and india. >> we're right on the threshold of high gas price volatility and we'll see it spike sooner rather than later. >> reporter: the price tracking website gasbuddy.com predicts a national average of $3.95 a gallon by memorial day. even higher in big cities. in atlanta, $4.60. $4.70 in los angeles, and in chicago, $4.95, the highest in the continental united states, which would mean that sticker shock at the pump -- >> 11 gallons, $44. >> reporter: -- may only get worse. john yang, nbc news, chicago. now overseas tonight in a place where any new trouble really could send oil prices

soaring, the u.s. navy is making a statement to iran in a critical oil shipping lane, the strait of hormuz. jim miklaszewski is in those waters tonight, getting a chance to see life onboard a u.s. carrier, the "u.s.s. abraham lincoln" where he got a closeup view of some potentially dangerous close encounters. >> reporter: it was daybreak as the u.s. aircraft carrier abraham lincoln got under way, led by a destroyer and a missile cruiser, high-powered protection, the carriers run through the strait of hormuz. as expected, the iranian military came out for a look. an f-27 plane makes a leisurely pass. shortly after, the bridge on the lincoln crackled to life. >> looks like he's out two miles. >> reporter: an iranian patrol boat was closing in fast.

within two miles of the carrier, iranian boat finally backed off. lincoln's commander, captain john alexander says his biggest worry is that incidents like this could eventually lead to a fatal miscalculation. >> they have the ability to take a shot at me at some point and that's what i worry about. >> reporter: it's a legitimate concern. we've now entered the most dangerous stretch of waters here for the american forces. just beyond that horizon is the largest gathering of heavily armed revolutionary guard fast boats, iranian submarines armed with torpedos and an entire shoreline of anti-ship cruise missiles. the iranians have already threatened to shut down the strait of hormuz and attack u.s. warships. but vice admiral mark fox says the u.s. military is prepared for anything iran throws at them. >> we're ready today.

>> you're ready today? >> this is the world we live in. what if it happened tonight? what would we do? we're prepared today. >> reporter: prepared for any potential miscalculation. jim miklaszewski, aboard the uss abraham lincoln in the strait of hormuz, nbc news. another bombing, israel is blaming iran. an apparently bungled attack as two explosions tore through a busy neighborhood, wounding four thai civilians. police captured two iranian nationals. and in syria, the regime unleashed more deadly fire on civilians in the city of homs today. some of it on the ground there said it was the most intense shelling since the regime escalated its crackdown more than a week ago. back in this country, it's not every day the number two official from a foreign country gets the full red carpet treatment in washington, but today someone did.

and the reason here is he is next in line to be the leader of china. that explained a lot about the welcome today. our chief foreign affairs correspondent andrea mitchell has more on today's charm offensive and the man we'll be hearing a lot more about. >> reporter: he is only china's vice president, but 58-year-old xi jingping is second in command in china's military and could be running china for the next decade. at the pentagon, xi was given full honors, even as china now challenges the u.s. in the south china sea. and vetoed the u.n. resolution against syria last week. today, xi faced human rights protesters at the white house. and criticism from president obama about human rights and unfair trade practices. >> with expanding power and prosperity also comes increased responsibilities. and so we want to work with china to make sure that everybody is working by the same rules of the road when it comes to the world economic system.

>> reporter: u.s. officials are sizing xi up. his background provides some clues. xi's father, one of china's original revolutionaries was purged by mao and jailed for being too pro reform. xi himself was exiled for seven years to a work camp during the cultural revolution. his daughter attends harvard. his nephew is at georgetown. and in 1985, xi went to iowa to learn how to raise hogs. >> he slept in the kids' rooms with "star wars" on the wall. he sat around our dining room table. we just gave him an iowa welcome. >> reporter: xi is said to like world war ii movies like "saving private ryan." and in china last summer, joe biden shot hoops with him. but today, biden pointedly said the u.s. and china do not always see eye to eye. >> it is a sign of the strength and maturity of our relationship

that we can be candid about our differences as we have been. >> reporter: but the bottom line is the u.s. and china are stuck with each other. china finances our debt, and we are their single biggest customer. and that makes it critical to figure out more about this new chinese leader. brian? >> andrea mitchell in our d.c. newsroom tonight. andrea, thanks. now we turn to presidential politics and some new twists in what is the continuing plot line this season in the gop. another candidate challenging mitt romney's frontrunner status. our political director and chief white house correspondent chuck todd with us with tonight. chuck, good evening. >> reporter: good evening, brian. as yogi berra might say, it's deja vu all over again. another month, another new conservative challenger rising to the top of the national polls to challenge mitt romney. this time, it's rick santorum. buoyed by upset wins last week in colorado, minnesota and missouri, rick santorum has done what many conservative candidates have done before him -- caught up to romney.

>> polls come and go. >> no fewer than four national poms out today have santorum, who was thumped out of the senate in 2006 by a whopping 18 points, now either slightly ahead or virtually tied with romney. for romney, it's a familiar spot, holding steady with his establishment republican supporting but failing to capture the hearts and minds of rank and file conservatives. but it's not for a lack of trying. >> i was a severely conservative republican governor. i understand that the battles we as conservatives must fight -- >> reporter: starting february 28, the republican race goes national. 18 contests over 15 days. but it's the next state up that's taking on extra significance, michigan. it's the state where romney was born and raised, a fact he's not afraid to remind voters of in this new ad. >> i grew up in michigan it was exciting to be here. i remember going to the detroit auto show with my dad. that was a big deal.

>> reporter: a loss in the state that he won four years ago and where his father george was a popular governor and auto executive would be devastating. exactly why the more conservative santorum is targeting romney's core weaknesses. >> a full spectrum conservative, rick santorum is rock solid on values issues. >> reporter: romney's allies are taking no chances. >> how did rick santorum actually vote? rick santorum, big spender, washington insider. >> reporter: one other tricky issue for romney to deal with in michigan -- his criticism of the auto bailout. romney defended that criticism again today in a "detroit news" op-ed. this is what he wrote. this is crony capitalism on a grand scale. the president says without his intervention, things would have been worse. i think without his intervention, things would be better. and so it goes. michigan may not be the shoo-in for romney that he hoped it would be. >> tough issue for folks there. chuck todd in washington tonight. chuck, thanks. also in washington tonight, lawmakers on both sides of the

aisle are expressing optimism they'll be able to pass an extension of the payroll tax cut without offsetting budget cuts that republicans had been demanding. this measure would also extend unemployment benefits and fix a problem that would slash medicare payments to doctors. it would add about $100 billion to the budget deficit. and some disturbing news about the state of this nation's voting system. in the presidential election year upcoming, the pew research center says 1 in 8 voter registrations in this nation is inaccurate. a quarter of eligible voters are not registered at all. 1.8 million dead people in this country are indeed still registered to vote. study says the problems here are not due to fraud, but they stem from disorganized and antiquated systems that could use some help from technology. whitney houston's body arrived at a new jersey funeral

home last night as her family made plans for a private memorial on saturday. the service is going to take place at the newark church where she sang as a child. it will be invitation only. there's no public memorial planned as of now. still ahead, as "nightly news" continues tonight, some all new allergy sufferers in the month of february. in some places where winter has yet to arrive, an allergy season really never went away. and there's news tonight about the nation's airports. which ones were the best and worst at getting you up and off the ground?

we're back now with news about this winter that has not yet arrived for a lot of people depending on where you live in this country. a lot of people believe something just isn't right about mother nature right about now. and while it is a welcome break far a lot of folks who don't miss the snow, for others, it's kind of an early allergy season. more tonight from our chief environmental foreign affairs correspondent anne thompson. >> it is a pretty site, spring flowers and some trees already blooming in many parts of the country during this unusually warm winter. but it is not a happy sound. allergy sufferers are already feeling the effects. >> i feel like you could scratch out your throat. >> i like the snow. it doesn't make me sneeze. >> reporter: this machine catches the pollen. >> this will measure anything that was in the air for the

previous 24 hours. >> reporter: the lab tech then hand counts the spores seen under the microscope. instead of single digits, dr. stanley fineman says the pollen count has reached 250. >> last year we saw it starting around the 20th of february. right now we're seeing it right after groundhog's day, which is the 2th of february. >> reporter: nationally, january was almost six degrees warmer than average. you can see the impact at georgia's calloway gardens. patricia collins says azaleas are way ahead of schedule. when should these azaleas bloom? >> they should bloom a month from now. >> reporter: but what if winter never comes? what if we don't get a stretch of cold nights or the rain and snow the plants and animals need. what happens then? >> well, if we don't have the rain, if we don't have the cold temperatures, some plants will not bloom correctly. especially a lot of our fruit trees. >> reporter: from a weather standpoint, it's a mixed bag

says the weather channel's jim cantore. >> you look at north dakota, they're not going to flood this year because they had below normal snow pack. down in the southeast, we may have more drought, especially in georgia and florida, and that could lead to more wildfires. >> reporter: the absence of winter, filling our eyes with beauty and aggravation. anne thompson, nbc news, pine mountain, georgia. up next here tonight, the alarming news about something a lot of women use every day. the story out tonight about a possible hidden risk in lipstick.

if you've been a frequent flyer this winter, you've had a lucky season. you can thank mother nature for the most part. december, as you may know, normally one of the worst months for on-flight performance because of snow and heavy passenger volume. this past december was the exception. on-time performance was the highest for a december in 17 years. bwi, baltimore washington, had

the highest on-time arrival performance, while newark had the lowest of the 29 busiest airports in december. newark also had the lowest on-time departure performance. tampa in florida was the highest. the president of the united states took a moment at the top of an event today to try to save his fellow american males from making a mistake he's apparently made in the past, forgetting the significance of today's date. >> good morning, let me start with a quick public service announcement for all the gentlemen out there. today is valentine's day. do not forget. i speak from experience here. it is important that you remember this and go big. that's my advice. >> again, it sure sounds like this was once a problem for him, taking no chances today on his official twitter account, he wished the first lady a happy valentine's day. a story tonight that will get

the attention of a lot of women in this country. the fda ran some tests on popular brands of lipstick, and 400 of them were found to contain trace levels of lead. the highest concentrations were found in l'oreal and maybelline brands. the fda says it doesn't consider the levels unsafe because it doesn't actually get consumed, but some consumer groups are protesting saying the fda should set limits on how much lead is allowed in cosmetics in the first place. we've put the entire list of all the brands and the test results on our website, nbcnightlynews.com. up next here this evening, the couple whose love story led to a big change in american law and life.

on this valentine's day 2012 a lot of young people coming up might not be able to fathom what happened to one couple in the 1950s. their interracial marriage was considered illegal and they were banished from their home state. now more than 50 years later, their name is forever attached

to a big supreme court case and their landmark love story is being told. our report tonight from nbc's rehema ellis. >> reporter: for richard and mildred, it was love at first sight, but it was also a crime when they married 54 years ago and they wanted to live in virginia. they were arrested at home in the middle of the night. >> they asked richard who was that woman he was sleeping with and i said i'm his wife and the sheriff said not here, you're not. >> reporter: their struggle to live together in a state that outlawed interracial marriage is the focus of a new hbo documentary, "the loving story." richard and mildred loving were convicted and exiled from virginia for 25 years. the soft spoken, unassuming couple never intended to make history. they just wanted to raise their three children together. >> she didn't want to be a rosa park. and he didn't want to be a martin luther king. i think the world needs to know it was because of my parents --

i'm sorry -- that they can marry any race they want. >> the civil rights movement gave the lovings hope. phil hirschcock argued on their behalf. the result, a landmark ruling in 1967, striking down the last of the segregation laws against mixed race marriage. >> the court was ready for us. they would not any longer tolerate such a deprivation of rights. >> after richard and mildred's death, director nancy versky felt compelled to document the couple's defiance. >> it was a story about race, but also such a profound love story. >> reporter: and a story of reluctant heros. >> how would you describe your mom and dad? >> very loving, stern, private, but with great determination. >> lose the small battles and win the big war. >> reporter: the film reveals a compelling portrait of the

lovings, who helped change america by simply living up to their name. rehema ellis, nbc news, new york. that's our broadcast on a tuesday evening. thank you for being here with us. i'm brian williams. we hope to see you right back here tomorrow night. we hope to see you right back here tomorrow night. good night. -- captions by vitac -- www.vitac.com good evening, everyone. i'm jessica aguirre. >> and i'm rob mathieu. in less than an hour, they expect to approve the contract for the 49ers stadium. >> that contract requires that they complete the stadium before