Fourteen states and one territory held nominating contests for the Democratic Party's candidate for president on Tuesday, the most pivotal day on the presidential primary calendar.
When the polls closed on Super Tuesday and results came in, it became clear that former Vice President Joe Biden had swept the Southern states, winning the primaries in Virginia, North Carolina, Alabama, Tennessee, Oklahoma, Arkansas and Texas, as well as Minnesota and Massachusetts, and had ended the night with the most delegates. Sen. Bernie Sanders came out on top in Colorado, Utah and his home state of Vermont, NBC News projected.
On Wednesday, NBC News declared Biden the apparent winner in Maine, though the race against Sanders in the state was a tight one.
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A quiet night for disinformation watchdogs
The Department of Homeland Security and disinformation experts monitoring social media had a relatively quiet night on Super Tuesday.
A senior official with Homeland Security's Cybersecurity and Infrastructure Security Agency said disinformation campaigns from foreign influencers appeared to maintain their usual daily level, with little primary day uptick.
Twitter removed a handful of accounts that spread false claims that coronavirus fears were disrupting or delaying voting. When NBC News reported several accounts to Twitter, the company confirmed that it took enforcement actions against the tweets and also said it took action against a small amount of other content violating its election integrity policies.
Facebook confirmed that it removed a small number of posts that violated its election content policies. Google didn't respond to a request for comment.
The fear of election interference from foreign and domestic actors following the well-documented Russian interference in 2016 has led to a state of heightened alert among election and security officials, social media platforms and researchers.
Though noise appeared low this primary day, that doesn't mean it can't perpetuate negative sentiment, said Joan Donovan, director of the Shorenstein Center's Technology and Social Change Research Project at Harvard University.
"Some aspects of trolling rely on hyping up particular emotions, and outrage and fear are two motivating emotions that may increase a claim's believability," Donovan said. "It's becoming increasingly apparent that the only group that can stop this kind of misinformation are platforms themselves." — Kevin Collier contributed reporting.
NBC News Exit Poll: Biden wins Democratic primary in Massachusetts, Warren's home turf
Joe Biden beat Elizabeth Warren on her home turf of Massachusetts in Tuesday's Democratic primary. Biden captured the lion's share of support from late-deciding voters. Roughly 4 in 10 voters who made up their minds in the last few days broke for Biden, according to NBC News Exit Poll results.
Biden does well with voters in the state who are looking for a candidate who can unite the country, and he wins nearly half of moderate or conservative voters there, as well as those ages 65 and older.
Biden also won strong support from voters who consider health care the top issue. But in contrast to Bernie Sanders' voters, a majority of those who voted for Biden in the Massachusetts primary oppose a single-payer plan.
Ilhan Omar, a Sanders supporter, throws shade at Warren
NBC News Exit Poll: Bloomberg voters like Biden, lukewarm on Warren, sour on Sanders
Amid calls from party officials that Mike Bloomberg consider dropping out in the wake of his disappointing results in today's primaries, results from the NBC News Exit Poll suggest that Joe Biden could enjoy a strong advantage among the former New York mayor's supporters.
Bloomberg voters in three states — California, Colorado and Virginia — were asked their opinions of the three other major candidates in the race. Only Biden is viewed favorably by a majority of Bloomberg voters: They give him 71 percent favorable and 23 percent unfavorable ratings. Elizabeth Warren is perceived favorably by a slim margin by Bloomberg voters, at 46 percent favorable and 44 percent unfavorable. And Bernie Sanders is highly disliked by Bloomberg's supporters: 38 percent favorable and 57 percent unfavorable.
In polls conducted in 12 of the 14 Super Tuesday states, nearly 1 in 5 Bloomberg voters said they could not guarantee that they would support the Democratic nominee in November regardless of who it is.
NBC News Exit Poll: Later deciders in Oklahoma broke for Biden
According to the NBC News Exit Poll, 50 percent of voters in Oklahoma decided which candidate to vote for only in the last few days. Among these late deciders, 41 percent voted for Joe Biden, while 18 percent opted for Mike Bloomberg, 16 percent for Elizabeth Warren and 15 percent for Bernie Sanders.
Long lines cause issues in California
Long lines, malfunctioning machines and limited polling staff meant many voters in Los Angeles struggled to cast their primary ballots Tuesday.
Mark Meuser, an election law lawyer, said he waited over an hour to cast his vote. He blames the longer wait times on a new voting system in Los Angeles County.
"The location I am at only has six voting stations and only 1/4 of the allotted staff actually showed up today," Meuser said in a Facebook post.
At the Ace Hotel in downtown Los Angeles, Mallory Brown, 29, told NBC News she waited three hours to vote.
She believes the long wait times were because voters had to wait in two lines, one outside the building and another inside.
"A lot of people just started leaving because they weren't getting updates about how long it would take or what the process was," she said. "People were just getting discouraged, and I saw a lot of people getting out of line as I was waiting."
NBC News Exit Poll: Most states show decline in first-time voters from Super Tuesday 2016
Across seven states conducting presidential primaries on Tuesday that held contests on Super Tuesday four years ago, there’s a dip on average in the share of voters participating in their first presidential primary, results from the NBC News Exit Poll show. That’s dispiriting news for Democrats, who are hoping for a surge of new voters to help power the party to victory in November.
The seven states — Alabama, Massachusetts, Oklahoma, Tennessee, Texas, Virginia and Vermont — all held Super Tuesday presidential primaries on March 1, 2016. The Democratic nomination contest then, as now, featured a spirited competition between well-known candidates.
The share of first-time primary voters is down in five of the states (Alabama, Oklahoma, Texas, Virginia and Vermont), up in Tennessee and flat in Massachusetts. Averaged across the seven states, first-time voters are 15 percent of the electorate in 2020, down from 17 percent in 2016.
NBC News Exit Poll: California voters are more liberal than in 2008
California’s Democratic electorate is more liberal than it was 12 years ago, the last time the state held an early primary. The NBC News Exit Poll finds that two-thirds of voters in Tuesday’s Democratic primary in California describe themselves as liberal. In 2008, only half described themselves this way.
Other key demographics, such as race and gender, are about the same in the 2020 California Democratic primary electorate as they were in 2008. Bernie Sanders won 44 percent of the liberal vote in Tuesday’s California contest, compared to 20 percent for Elizabeth Warren, 17 percent for Joe Biden and 8 percent for Mike Bloomberg, according to the poll.
Hillary Clinton won the last two contested California primaries, by 8 points over Barack Obama in 2008 and by 7 points over Bernie Sanders in 2016. There was no exit poll four years ago when Clinton wrapped up the delegate count the day before the state’s June primary. In 2008, the primary was held in early February when the nomination was still in question.
Most California voters hold positive views of Sanders (70 percent), Warren (67 percent) and Biden (62 percent). Just 32 percent of voters, in contrast, hold a positive view of Bloomberg.
Biden won late deciders by 41-to-30 percent over Sanders. Just 18 percent of California primary voters made up their minds in the last few days; most voters cast their ballots before Tuesday.
ANALYSIS: Biden finds his mojo on Super Tuesday
Talk about finding mojo.
Four days removed from a winless record in the fight for the Democratic presidential nomination, former Vice President Joe Biden barreled through a string of Southern states Tuesday to shovel piles of delegates into a campaign train that launched out of South Carolina on Saturday and has been picking up steam ever since.
"We were told when you get to Super Tuesday, it may be over," Biden told supporters Tuesday night, his voice full of excitement. "Well, it may be over for the other guy."
The centrist's early victories in Virginia, North Carolina, Alabama and Tennessee — fueled by large majorities among African American voters — promised to put him in a strong position to fight Vermont Sen. Bernie Sanders for the right to take on President Donald Trump in November. His better-than-expected showing in New England and along I-35 in the heart of the country threatened to knock Sanders and the progressive wing of the Democratic Party on its heels.
"What we are watching is the voices of African American and other diverse communities being heard loudly around the nation," said Marcus Mason, a Biden donor and former senior director of government affairs for Amtrak. "South Carolina was not a firewall, but a foundation for what was to come."
NBC News Exit Poll: Voters in five states support free college tuition, 'Medicare for All'
Voters across five Super Tuesday states — California, Texas, North Carolina, Tennessee and Virginia — expressed widespread support for free tuition at public colleges and replacing private health insurance with a single payer system, according to NBC News Exit Poll results. Taken together, half of these Democratic primary voters favor both policy proposals, while just 1 in 5 favor neither.
Among those who want both free college and "Medicare for All" as the nation’s only health plan, 49 percent supported Bernie Sanders today. Just 20 percent of this group backed Joe Biden, and 17 percent voted for Elizabeth Warren. But among those who do not support either idea, 44 percent backed Biden, while 23 percent voted for Mike Bloomberg and 9 percent supported Sanders.
Those who want both policy options enacted are more likely to be younger than 45. There is also more support for both proposals among Latino voters than among non-Latinos of any race.
Fully 3 in 4 primary voters who call themselves very liberal back both "Medicare for All" and free college, compared to half of those who are somewhat liberal and just over one-third of moderates and conservatives.