Former Vice President Joe Biden won decisive victories March 10 in the Michigan, Missouri and Mississippi primaries over his last remaining rival for the Democratic presidential nomination, Vermont Senator Bernie Sanders. Biden and Sanders were virtually tied in the other large state voting Tuesday, Washington state.

Biden addressed supporters at his campaign headquarters in Philadelphia Tuesday night, speaking as though the contest for the nomination was over. He spoke directly to the Sanders campaign, praising Sanders personally and urging his supporters to join a united Democratic Party effort to defeat President Trump in November.

In a chilling passage of a very brief speech, Biden declared that a Democratic president would “make clear to our adversaries that we will stand fast in restoring world order. That’s an American responsibility.” This underscores the real axis of the campaign that the Democrats intend to wage in 2020: to brand Trump as a Russian stooge who is responsible for the disruption of US-led alliances like NATO and to reassert the role of Washington as the leader of world imperialism.

Sanders returned to his home in Burlington, Vermont, where he held no campaign events and did not speak to supporters or the media about the outcome of Tuesday’s voting. Both Sanders and Biden cancelled Tuesday night rallies scheduled for Cleveland, Ohio, after the Ohio governor asked them not to hold large indoor events because of the coronavirus emergency.

The results place the Sanders campaign on life support with virtually every Democratic Party officeholder and operative lining up for Biden as the presumptive nominee. Biden extended his lead among pledged delegates to the Democratic nominating convention to about 150, roughly 800 to 650.

Missouri and Mississippi were called by the television networks just after polls closed and Michigan was called for Biden a half hour after polls closed in that state and with just 30 percent of the vote reporting.

Biden trounced Sanders in Mississippi, where the Democratic electorate is heavily skewed to older African American voters. Biden claimed more than 81 percent of the vote, while Sanders was in danger of failing to clear the 15 percent threshold to win even a small share of the state’s 36 delegates.

In Missouri, where Biden received the endorsement of former governor Jay Nixon as well as Representative Emanuel Cleaver, a one-time chair of the Congressional Black Caucus, and other leading Democrats, Biden won 60 percent of the vote to Sanders’ 35 percent, giving him the lion’s share of the delegates.

However, the biggest loss of the night for Sanders was in Michigan, where he had won a narrow victory over former Secretary of State Hillary Clinton in the 2016 presidential primary contest, in a stunning upset that prolonged the nomination contest for months.

On Tuesday night the result was nowhere near as close, with Biden leading in nearly every county, rolling up a margin of more than 100,000 votes in the tri-county Detroit metropolitan area. Sanders, who won 73 counties in 2016, including all the rural areas, did not win a single county in 2020.

As in many other states, Biden’s victory was due in large part to huge majorities among African-American voters, with exit polls showing him with a 66 percent to 34 percent margin over Sanders. In 2016, Sanders was able to overcome a similar showing by Hillary Clinton among black voters, by winning huge margins in white working class areas.

There was a significant shift to Biden in more upscale, middle class areas such as Livingston County and Oakland County. Even in Washtenaw County, home to the University of Michigan and Eastern Michigan University, Biden bested Sanders thanks to his support in upscale precincts outside the student residential neighborhoods.

While all precincts reporting, Biden led Sanders in the Michigan delegate count by 71 to 51, and he stood to increase that majority with three more delegates to be awarded.

In each of the three states where vote counting was completed Tuesday night, voter turnout was up from 2016, but Sanders' vote totals were down compared to his numbers four years ago. This contrast was sharpest in Michigan, where voter turnout rose more than 10 percent, from 1.09 million in 2016 to 1.21 million this year, but Sanders’ vote dropped from 599,000 in 2016 to 576,000 in 2020.

The perspective of the Sanders campaign, that he could transform the Democratic Party with an influx of new, younger voters, has proven an abject failure. In barely two weeks, the Democratic Party leadership has intervened decisively to block Sanders and elevate Biden, the most right-wing of the major Democratic presidential hopefuls, into a virtually insurmountable position as frontrunner for the nomination.

In the other contests Tuesday Sanders defeated Biden in the caucuses in North Dakota, which offered just 14 delegates, while Biden beat Sanders in the primary in Idaho, where 20 delegates were to be selected. The primary in Washington state, based entirely on mail ballots, showed a virtual tie with two-thirds of the vote counted, meaning that neither candidate would gain a significant advantage once the distribution of 89 delegates is determined.

It is expected that once all the delegates are awarded from Tuesday night that Biden will have significantly increased his lead over Sanders, with the likelihood of even bigger gains in next Tuesday’s primaries in four large states—Florida, Illinois, Ohio and Arizona—which account for 577 delegates combined.

Even as results were still coming in Tuesday night, leading figures in the Democratic Party were voicing public demands for Sanders to wrap up his campaign and for the Democratic National Committee (DNC) to bring the primaries to a quick end.

South Carolina Representative James Clyburn, the House majority whip, speaking to NPR shortly after the polls had closed in Michigan, Missouri and Mississippi, called for the DNC to cancel all future planned debates if Biden swept Tuesday’s races.

“I think when the night is over, Joe Biden will be the prohibitive favorite to win the Democratic nomination,” Clyburn declared. “If the night ends the way it has begun,” he continued, then it would be time to “shut this primary down,” with the DNC stepping in to call off the debates.

Clyburn, whose endorsement of Biden was critical to his victory last month in South Carolina and the resurrection of his moribund campaign, expressed concern that further debates and primary contests would be bad for Biden because he “gets himself in trouble.”

The DNC has announced Tuesday that the next debate, scheduled for Sunday, March 15 in Phoenix, Arizona, would be held with no audience or press present as a precaution against the spread of coronavirus. The two remaining candidates who qualify under the DNC’s rules, Sanders and Biden, if the debate goes forward after Tuesday’s results, would appear on stage together facing a panel of moderators and an empty auditorium.