WASHINGTON — It was a strong night for former Vice President Joe Biden in Tuesday night's primaries.  

Voters went to the polls in six states on Tuesday, handing Biden wins in Michigan, Idaho, Mississippi and Missouri. 

Sen. Bernie Sanders won North Dakota.

Washington’s primary was too early to call, and because all votes there are cast by mail or by dropping them off in a ballot box, many ballots were marked for candidates who have since dropped out of the race.

"Just over a week ago, many of the pundits declared that this candidacy was dead," Biden said Tuesday night. "Now we're very much alive. And although there's a way to go it looks like we'll have another good night." 

As it stands Wednesday morning, Biden is sitting at 823 delegates and Sanders has 663. 

Florida is up next Tuesday with its 219 pledged and 29 super delegates at stake.

A total of 1,991 delegates are needed for the nomination. A Biden win in Florida could all but seal the nomination.

Even as the contours of the race came into shape, however, new uncertainty was sparked by fears of the spreading coronavirus. Both candidates abruptly canceled rallies in Ohio that were scheduled for Tuesday night. 

That set the stage for Biden’s remarks in Philadelphia, while Sanders flew home to Vermont and didn’t plan to address the public.

Sanders’ campaign also said all future events would be decided on a case-by-case basis given public health concerns. Biden, meanwhile, has canceled his Thursday visit to Tampa. Instead he will be in Delaware to discuss the coronavirus.

The Democratic National Committee also said that Sunday’s debate between Sanders and Biden would be conducted without an audience.

TESTY EXCHANGE IN MICHIGAN

Though he’s celebrating a growing delegate lead, Biden is still confronting voters who question his positions, which include a gun control plan that reinstates an assault weapons ban and includes a voluntary buyback program for assault weapons.

That issue was at the center of a testy exchange with a worker while Biden was rallying earlier Tuesday in Detroit.

The man accused him of “actively trying to end our Second Amendment right.” Biden shot back, “You’re full of shit,” but went on to say that while he supports the Second Amendment, “Do you need 100 rounds?”

Information from the Associated Press was used in this report.