nbc news jennifer johnson shoulder travelers, no social distancing. at u.s. airports as several hours to be screened fo process. >> hundreds and hundreds of people. that's exactly what you don't want in this pandemic. >> reporter: complicating the situation, a handsful of tsa officers are now testing positive for the virus. as ohio bars and restaurants are closed indefinitely, the leading infectious disease doctor is raising the possible of a 14-day nationwide lockdown keeping people out of public places. >> i think we should be overly aggressive and get criticized for overreacting. >> reporter: he says there are no plans yet for domestic travel restrictions. the white house promising millions more tests will be available soon. >> we will now have access in the days ahead to more than 2,000 labs across the country that have the equipment today to process coronavirus tests. >> reporter: new york's governor is calling on the president to activate the military to build makeshift medical centers before hospitals are overrun. >> use them to come in right now. iden

jennifer johnson, nbc news, washington. >> and if you have questions, we have answers. this monday, catch an nbc bay area special report, understanding coronavirus. we take an in-depth look at the worldwide outbreak and how it reached the bay area. we'll also clear up common ru misconceptions. it airs this monday at 7:00 or you can watch it now on nbc bay area.com. >>> the race for the democratic presidential nomination is a two-candidate race. both men very busy working to solidify their support ahead of tuesday's primaries. bernie sanders in michigan, a state he won back in 2016, joe biden picked up a big endorsement in california senator kamala harris. story from nbc's dan scheneman. >> reporter: joe biden on the campaign trail in mississippi, speaking to other to an african-american congregation ahead of the state's primary. >> you can make the choice. >> reporter: the former vice president also gained the support of another former rival. >> i have endorsed him and i'm going to do everything i possibly can to help him win. >> reporter: senator sanders also picked up

drastic measures to stop the deadly virus jennifer johnson, nbc news, washington >>> parents across the country are scrambling trying to juggle hie child care and their jobs as schools announce closures. in new york city parents got less than 24 hours notice. here is nbc's morgan chest i can. >> reporter: the schools are closed from coast to coast the precautionary step for covid-19 forcing parents to figure out what comes next. >> it's frustrating. it's anxiety-inducing. >> how will they do work and keep up? >> you know, it's kind of hard to kind of figure it out you know, it's kind of scary >> reporter: at least 25 statewide school closures have been issued impacting around 27 million students facing mounting pressure from teachers and parents new york's public school system will close. schools like los angeles and houston have done the same. >> i'm afraid it will be longer than that. unfortunately, at this time, i don't know what we'll do >> reporter: both work and with three kids out of public school, the concern is equal parts child care and school work. >> our schools don't push t

jennifer johnson has more. >> reporter: with the number of cases of covid-19 rising rapidly, one in fourmericans sheltering at home, president trump announcing major steps to help struggling states says masks and life-saving equipment is being sent out and heaviest hit will get assistance from the national guard. >> instructed fema to supply four large federal medical stations with 1,000 beds for new york eight large federal medical stations with 2,000 beds for california and three large federal medical stations and four small federal medical stations with 1,000 beds for the state of washington. >> reporter: president has also declared washington state a disaster area along with new york nation's top infectious disease doctor is warning the worst is yet to come. >> we're going to get hit, no doubt about it things we're seeing in the country, this physical separation as we're preventing influx of cases from coming in, i think that's going to go a long way to preventing us from coming an italy. >> reporter: president sending warm wishes to rand paul, first u.s. senator to test positive for

that stood out, obviously we have the leaders like abbey johnson who is the ceo of fidelity and jennifer johnsonwere debbie devira who is the cfo of gm and the reason that she stood out was gm is squarely in the crosshairs of this coming slowdown but it also has this issue of stranded -- potential stranded assets with billions tied up in internal combustion engine plants. one of your frequent guests is nancy lazar, brilliant economist will have a lot more to hear about her as we sort of navigate the slowdown on wall street. maria: i think our viewers heard about her first on this program. >> i think maybe they did. maria: i've been talking about corner stone macro for many years, certainly nancy l lazar,i agree, she's fantastic. >> two more people i want to mention, which are mindy luber of sir reec series which is a cy that encourages people to report about climate change. goldman sachs has a big push to take companies public when they have one diverse board member. maria: did they talk about how hard it was to muscle through? i mean, dagen and i have been covering wall street for 25 years but

jennifer nuzzo is infectious disease epidemiologist at johnson hopkins university. what did you take away from this briefing we just had? >> well, it's interesting how the concept of testing and the talk of testing is not being resolved. and i think there are a number of different ideas here. first of all, i want to stress that this test is not like you can take it once and then you're clear. this is something that potentially if you take it too early, you could get, you know, an incorrect impression about whether or not you're infected. and you could be subsequently repeated. so it's important to think about that in the context of how many tests we might need, and also how they're going to be screening those passengers on the cruise ship because it makes sense to start with the people who have symptoms, because you're more likely to get a correct test result. >> ron klain is with us, the former ebola response coordinator during the obama administration. what was your takeaway? were you reassured by what you heard? >> i thought that was really disappointing, to say

jennifer granholm. we think we're going to wage a competitive race. i'll be in michigan. we're coming up there next week. looking forward to it. >> final question as i'm sure you're aware, senator ron johnson is now subpoenaing someone connected to the company burisma that hunter biden worked for. do you believe these investigations are politically motivated? >> yes, i believe they're politically motivated and i believe this is a test for the media, for reporters and the political space as a whole. this is a conspiracy theory, concocted by the trump campaign and republicans because they are scared of facing joe biden at the ballot box in november. folks should not take the bait. these are key dee bufrned conspiracy theories and it is despicable that anyone would even give this any air. so we're going to continue to beat back these lies. and speak truth to power and facts, but we implore the media and folks across this country to not take the trump campaign's bait. >> will biden say my son shouldn't have been working for that company? >> jim, to be clear, this is a nonstarter. there is nothing -- hunter -- there is nothing wrong that vice president biden did, this is not about hunter biden