Six more states head to the polls for Democratic primaries

Biden and Sanders focus on delegate-rich Michigan - NBC's Sarah Dallof reports.

DETROIT, Mich. (KYMA, KECY/NBC News) - It may not be Super Tuesday, but it's a big Tuesday for former Vice-President Joe Biden and Senator Bernie Sanders, (I) Vermont.

Biden drew big crowds in the Motor City...

"Wall street didn't build this country. You all built the country."

And tangled with one voter over gun rights. Still, he received a warm welcome from autoworkers.

Bernie Sanders was also greeted with enthusiasm. He thanked supporters and made his final pitch to voters.

"We are the campaign of energy and excitement."

Biden won ten states last week. He hopes he can deliver a knockout blow in Michigan.

"Michigan I'm counting on you in a big way."

It's the state with the most delegates in this round of voting.

The latest polls show the former vice-president with a double-digit lead over the Vermont senator. But Sanders overcame a similar lead in 2016, and went on to a surprise win over Hillary Clinton.

President Donald Trump ultimately went on to win the state. That victory was top of mind for Democratic voters Tuesday.

"Biden, Bernie Sanders, Biden, because I want to know who is going to beat Donald Trump." said one Michigan voter.

As they head to the polls to pick a Democratic nominee...and they hope, a new President.

Five states are also holding Republican primaries. Donald Trump is expected to easily win them all.