Former Vice President Joe Biden predictably swept the black vote in March 10 states, but he also scored key wins among white voters — most notably in the battleground state of Michigan.

On Wednesday morning, progressive Sen. Bernie Sanders was lagging behind Biden in every single county in Michigan, Missouri, and Mississippi, according to Kyle Kondik, managing editor of Sabato’s Crystal Ball. (Sanders won North Dakota and some Idaho counties; Washington state has yet to be called.) Sanders was expected to lose Mississippi and Missouri, but he contested Michigan fiercely after narrowly winning it in the 2016 primary.

Biden’s dominance with the black vote has been the prevailing story of Super Tuesday and beyond, but on Tuesday, the former vice president also cleaned up with the suburban white voters who propelled Democrats to victory in 2018 — and who he needs to win a general election in 2020.

In doing so, he signaled he may be on his way to building the sort of coalition the Democratic Party will need to be competitive in the general election. And on March 10, at least, these three groups came out for Biden and helped bolster his claim to the nomination.

White working-class voters, and white voters in suburbs

White working-class voters in Michigan were what propelled Sanders to a narrow and unexpected victory over Hillary Clinton in 2016, but 2020 exit poll data shows he couldn’t count on them this year.

While the vast majority of Michigan’s Upper Peninsula voted for Sanders over Clinton in 2016, they went for Biden in 2020, according to Cook Political Report editor Dave Wasserman.

The big story in Michigan: the shifting allegiance of working-class white Dems since '16.



Pretty much the entire Upper Peninsula voted for Sanders in '16. So far, huge Biden margins. — Dave Wasserman (@Redistrict) March 11, 2020

Whereas working-class white voters had propelled Sanders to his 2016 win, “This year, they have been his undoing,” tweeted Economist pollster and journalist G. Elliott Morris, adding Sanders was down about 30 points from 2016 in the Michigan counties with large numbers of non-college-educated white voters.

Bernie's 2016 campaign was fueled by working-class whites in the Rustbelt. This year, they have been his undoing. Sanders is down by about 30 points compared to 2016 in MI counties with the highest shares of non-college whites, and down by just 5 in those with the least. — G. Elliott Morris (@gelliottmorris) March 11, 2020

And it wasn’t just working-class voters: Sanders also lost more well-educated suburban voters who helped propel Democrats to a win in the 2018 midterms. As Politico reporter Tim Alberta noted, Democratic turnout doubled in Livingston County, a richer (and traditionally Republican) suburban county that’s part of a congressional district flipped by a moderate Democrat in 2018.

FORGET ABOUT MACOMB COUNTY



It's not the bellwether anymore (sorry @zackstanton)



Look at LIVINGSTON: wealthy, well-educated, suburban, at the heart of The Great Realignment



In 2016 D primary, ~17,500 votes cast



Tonight, ~27,500 votes cast



50% turnout spike in Slotkin Country. — Tim Alberta (@TimAlberta) March 11, 2020

Ahead of voting, political experts in the state were clear: Even though Biden’s dominance on Super Tuesday could be chalked up to his solid support with black voters, he could not count on black voters to win him Michigan because there aren’t enough black voters to deliver decisive wins in the state (the Washington Post exit poll showed they account for about 18 percent of the vote, compared to 72 percent white voters).

“Biden’s support will not depend on Detroit as much,” Michigan State University political scientist Matt Grossman told Vox recently, adding “Biden is doing better among white voters statewide.”

Biden needed white voters as well, and he got them.

Black voters in Mississippi, Missouri, and Michigan

Mississippi was the only state resembling the Southern Super Tuesday states where Biden romped last week. He won the state vote easily on Tuesday night, 81 percent to Sanders’s 14 percent.

Black voters make up the vast majority of the Mississippi Democratic electorate, and Biden won 87 percent of those voters, compared to Sanders at 10 percent, according to the Washington Post’s exit poll.

In Missouri, where black voters make up 17 percent of the Democratic electorate, Biden won them by 72 percent, compared to 24 percent for Sanders (Biden also won white voters in Missouri, 56 percent compared to 36 percent for Sanders).

And in Michigan, Biden won the black vote by 66 percent, compared to 27 percent for Sanders. While Sanders won Michigan’s Latino vote 53 percent to 39 percent for Biden, Latinos only account for 6 percent of the electorate — not enough to bolster Sanders on Tuesday night.

Older voters

The age gap between voters who support Biden and those who support Sanders could not be clearer Tuesday night.

The Washington Post exit poll on March 10 showed Biden winning voters 65 and older by 51 points, and Sanders winning voters aged 18-29 by 57 points. The problem for Sanders was older and middle-age voters turn out more reliably than young ones — a problem he has acknowledged.

“Let me tell you the bad news, to be honest with you, young people vote at much lower rates than older people,” the senator told voters in Missouri on Monday. “I hope all of the old people vote, that’s great, but I want young people to vote at the same rates.”

In Missouri, turnout spiked among those 65 and older, compared to 2016 — a boost for Biden.

Results elsewhere were similarly lopsided by age. In Michigan, Sanders won both voters aged 18-29 and 30-44 (both groups totaling about 38 percent of the Democratic electorate) but lost out on voters aged 45-64 and 65 and over — which together account for 62 percent of that state’s electorate.

It’s well-established fact that older voters turn out more reliably than younger voters, but the youth vote is considered a sign of voter enthusiasm — and was a key part of former President Barack Obama’s winning coalition in 2008.

Biden won handily without young voters this time, but he may need them come November.