While the evening was not the worst-case scenario for the Bernie Sanders campaign, it was certainly a blow that has narrowed the democratic socialist’s path to the nomination down to a sliver.

Former Vice President Joe Biden won four states, Mississippi, Missouri, Michigan, and Idaho, some by landslide margins. Sanders won only the North Dakota caucus, and holds a lead of a few thousand votes in Washington state, a race that is still too close to call.

The primary results prove once again that Biden’s standing among African American voters has been his saving grace. It was this demographic that salvaged his campaign after poor showings in Iowa and New Hampshire, and which gave him a blowout victory in South Carolina. Now, last night, Biden won the deep south state of Mississippi with over 81% of the vote. Sanders didn’t even clear the 15% margin of viability.

Sanders’ inability to connect with people of color was his handicap in his original 2016 presidential run. After spending three years trying to correct this, he had made noticeable gains among black voters and Hispanics. While he remains the favored candidate of Hispanics, any marginal gains among black voters have been wholly conceded to Joe Biden.

But it isn’t just with minorities that Biden is dominating. The biggest test of last night was Michigan, the rest belt state that is the crown jewel of the Democratic general election strategy. In 2016, Sanders made up a twenty-point deficit to defeat Hillary Clinton in the state. Last night, however, Biden won the state by a sixteen-point margin.

Biden’s victory isn’t just because of the black vote, but a swathe of demographics. Joe Biden won among both college-educated voters and non-college educated voters. In Michigan, he also outperformed Sanders in the rural counties that had previously been the Vermont senator’s base.

With an ability to unite both black voters and moderate suburban voters, Joe Biden has created a coalition strong enough to be highly competitive in the challenge against President Donald Trump.

So where does this leave Bernie Sanders?

The Senator addressed the media this afternoon on the state of his campaign. Sanders emphasized his support among young voters (contrasted with Biden’s support among the elderly) and the popularity of his ideas on health care like Medicare for All. “While our campaign has won the ideological debate, we have lost the debate over electability,” Sanders said.

Bernie Sanders’ plan to win that debate is to win the physical debate, planned for Sunday evening. It will be the first one on one debate of the primary, with only Sanders and Biden included. Due to concerns about the coronavirus, there will be no live audience for the debate, which will feature the two candidates sitting at a table together instead of standing behind a podium.

“Donald Trump must be defeated, and I will do everything in my power to make that happen,” Sanders concluded.

Hunter DeRensis is a senior reporter for the National Interest. Follow him on Twitter @HunterDeRensis.

Image: Reuters.