Joe Biden surged to a surprise victory in delegate-rich Texas after winning nine other states in a dominant Super Tuesday showing, according to NBC News projections, though the biggest prize of the night, California, remained unclaimed.

There are 228 delegates at stake in Texas, more than in any other state voting Tuesday except for California.

The results from the night indicate that the Democratic primary has essentially become a two-man race between Sanders and Biden. The race in California, where 415 delegates are up for grabs, remains too early to call as ofearly Wednesday, according to NBC News, though Sanders leads.

Sanders prevailed in his home state of Vermont and in Colorado and Utah, according to NBC News, and had been polling ahead in Texas prior to Super Tuesday. But Biden, after running neck-and-neck with Sanders in the Lone Star State early Wednesday, prevailed in the popular vote. He picked up 56 delegates, while Sanders netted 47 as of 5 a.m. ET Wednesday. It could take days, and possibly longer, for those all-important delegates to be fully allotted to the candidates, however.

Biden, for his part, also won the Virginia, North Carolina, Alabama, Tennessee, Oklahoma, Arkansas, Minnesota and Massachusetts Democratic primaries, according to NBC News projections, sweeping the South with his strength among black voters and making an inroad in the upper Midwest after a key endorsement from Minnesota Sen. Amy Klobuchar. His projected wins in Massachusetts and Minnesota were unexpected. He was also the apparent winner in the Maine Democratic primary, according to NBC News.

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As of 3:15 p.m. ET Wednesday, Sanders led Biden in California 33.6 percent to 24.9 percent with 54 percent of the vote in.

Biden, at a rally in Los Angeles on Tuesday evening, made no secret of his happiness with the evening's results so far.

“It's a good night, a good night,” the smiling former vice president told supporters. “They don’t call it Super Tuesday for nothing.”

Sanders, for his part, had projected optimism at a rally in Essex Junction, Vermont, and previewed his prospects in California.

“Tonight, I tell you with absolute confidence, we are going to win the Democratic nomination and we are going to defeat the most dangerous president in the history of this country,” he said.

“I don’t know what's going to happen later tonight. We are doing well in Texas right now, we won Colorado and I’m cautiously optimistic that later in the evening we can win the largest state in this country, the state of California,” Sanders added.

A total of 1,344 pledged delegates will ultimately be awarded as a result of the biggest voting night of the primary calendar. The goal of the Democratic presidential primary is to amass delegates to capture the nomination, not popular votes, and winning states does not necessarily mean a candidate will win the most delegates.

As of 3:15 p.m. ET Wednesday, Biden led in the pledged delegate count with 513. Sanders had 461.

Elizabeth Warren, who lost her home state of Massachusetts to Biden but was above the threshold to receive delegates in at least four states, had just 39, while Mike Bloomberg — who earned his first delegates after NBC News projected a win for him in American Samoa's Democratic caucuses — had 18.

To earn pledged delegates, a candidate must get at least 15 percent support statewide or in an individual congressional district. Delegates are awarded proportionally in each state to candidates who surpass those thresholds.

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Biden’s narrow win in Texas was driven by older voters.

About 25 percent of Democratic primary voters in in the state this year were 65 or older (about twice the level it was in 2008), according to the NBC News exit poll, and nearly half of those voters went for Biden in the state.

Biden's wins in Virginia, North Carolina, Alabama and Tennessee, meanwhile, were fueled in large part by strong support from African American voters, according to early results from the NBC News exit poll in the states.

In Virginia, Biden won the support of 63 percent of black voters, the poll showed. By comparison, only 17 percent of black voters backed Sanders, according to the survey. The former vice president also won solid majorities among those 45 and older, as well as moderates and conservatives.

In North Carolina, Biden was the overwhelming favorite of the state's black Democrats, having received about 6 in 10 of votes cast, according to the poll. His performance among African Americans there was far ahead of his nearest rival, Sanders, who received just 16 percent of the black vote.

In Alabama — the state with the highest proportion of black voters on Super Tuesday — 72 percent of African American voters backed the former vice president, the poll showed. That level was even higher than the 61 percent of black voters who supported him in South Carolina on Saturday.

In Tennessee, 62 percent of black voters backed Biden, the poll showed. He also won majorities in the state among military veterans, moderates and conservatives, as well as voters 45 and older.

Biden's support from African American voters in states outside the South, however, was weaker.

In California, Colorado, Massachusetts, Maine, Minnesota and Vermont, black voters were about half as likely as those in the South to support Biden, according to early results from the NBC News exit poll.

There was a large division by age: Black voters under 45 are about three times as likely to support Sanders than those 45 and over. Black voters 45 and over, on the other hand, are nearly 30 percentage points more likely to support Biden than Sanders, according to the poll.

Six in 10 voters in Tuesday's Democratic presidential primaries care most about nominating a candidate who can beat President Donald Trump in November, according to the NBC News exit polls conducted in 12 of 14 Super Tuesday states across the country. Those voters favor Biden over Sanders by a margin of 36 percent to 25 percent.

Sanders, meanwhile, did well among first-time Democratic primary voters — getting 43 percent of their support compared to 24 percent for Biden — but those voters represented just 13 percent of the Super Tuesday electorate.

In Texas, Sanders performed strongly among Latino voters, getting 41 percent of their support, according to results from the NBC News exit poll.

There were reports of long lines at polling locations throughout Texas and in California — where there were also reports of broken voting machines.

Voters in Los Angeles in particular faced long lines, malfunctioning machines and limited polling staff, creating problems for those trying to cast primary ballots in the state with the largest delegate prize on Super Tuesday. Some voters said they waited in line as long as three hours before they were able to vote.

The race for the Democratic nomination changed rapidly in the days leading up to Super Tuesday. On Saturday night, Biden, who had poor finishes in the Iowa caucuses and the New Hampshire primary, won the South Carolina primary in a landslide victory. His big win — which signaled that he could be the presumptive favorite in the party’s moderate lane — prompted Pete Buttigieg to exit the race Sunday and Klobuchar to follow suit Monday. Both endorsed Biden on Monday.

Many voters in Tuesday's Democratic presidential primaries waited until just recently to pick a candidate, according to early results from the NBC News exit polls — and Biden got support from nearly half of them.

Riding his wave of endorsements, Biden was favored by 47 percent of Super Tuesday voters who said they picked a candidate in the last few days. He left Sanders, Warren and Bloomberg far behind with these late-deciding voters. By contrast, Sanders built a comfortable lead over Biden, 37 percent to 25 percent, among voters who picked a candidate earlier than the last few days.

About 1 in 10 voters said they waited until Tuesday to make their choice, and another 19 percent of voters decided in just "the last few days."

Klobuchar's endorsement of Biden seemed to especially impact voters in her home state. According to the NBC News exit poll, Biden drew 49 percent of the late-deciding vote in Minnesota — more than twice the amount that Sanders did at 21 percent.

Klobuchar remains extremely popular in Minnesota — 75 percent of the state's Democratic voters expressed a favorable opinion of her, according to the NBC exit poll on Super Tuesday — suggesting her endorsement had some pull.

Biden also rode his momentum to a win in Massachusetts, where Warren and Sanders had been battling. He captured the lion’s share of support from late-deciding voters, with 43 percent of those who made up their minds in the last few days breaking for him, according to NBC News exit poll results.

Warren, who finished third in her home state and who was all but certain to win zero Super Tuesday states, urged supporters at a rally in Detroit to "cast a vote from your heart" and said that "the pundits have gotten it wrong, over and over."

Meanwhile, Bloomberg, following his win in American Samoa — his only one of the night — told supporters at a Florida rally that "no matter how many delegates we win tonight, we've done something no one else thought was possible."

"In three months, we went from 1 percent to being a contender for the Democratic nomination," he said.