Unity tour rolls on for Democrats as ex-rivals join Biden in Michigan

"Will you stand with me now for Joe Biden? Will you stand with me right now in the name of healing?" Booker said, his voice rising as he urged Democrats to join in vaulting Biden to the Democratic nomination.

"He is part of us, he will never look down on us," Booker said. "He will lift us up."

Booker was just the opening act, as hundreds packed a gymnasium at Renaissance High School in Detroit Monday evening to see Booker, Biden, and Harris, one of the largest events for Biden since he declared his campaign for President.

"I am so proud to endorse Joe Biden for President of the United States," Harris said, as she drew the loudest cheers from the crowd.

"I believe in Joe," the California Democrat added, as she joined Booker in extolling the virtues of Biden.

As Biden entered to loud cheers, he joined hands with Booker, Harris, and Gov. Gretchen Whitmer (D-MI).

"Michigan, I'm counting on you!" Biden said to cheers, as he bragged about how he's turned out more voters than Sen. Bernie Sanders (I-VT) in the last two weeks.

The appearances of Booker and Harris on the campaign trail with Biden capped an extraordinary ten days in the Democratic race, as they followed on last week's endorsements by Pete Buttigieg, Amy Klobuchar, and Michael Bloomberg.

Biden supporters said they were glad they stuck with him.

"We had some times there where it looked a little rocky," said the Mayor of Detroit, Mike Duggan, noting Biden's bad finishes in Iowa and New Hampshire.

"People said to me, 'how come you're still with him, he's losing, you should switch,'" Duggan said, recounting Biden's support for the auto bailout after the 2008 Wall Street Collapse.

"It was Barack Obama and Joe Biden who went in and fought for us," Duggan said to loud cheers.

"I remember Hillary was up 23 points," Biden said, reminding everyone that the polls were drastically wrong in 2016, as Bernie Sanders won a 4-point upset over Clinton, further extending the Democratic race.

"This could be the day we remember where turned the whole nation around," Booker said.

"Michigan is an important contest," Biden said on Monday, "because the outcome of Michigan in November may determine who the next President of the United States is going to be."

"This is one of a handful of states that may end up determining this election," Biden added.

While Biden has been assembling a coalition of blacks, disaffected suburban Republicans, and moderate Democrats, Bernie Sanders has not been able to follow through on his prediction that a massive turn out of young people would power him to victory.

"I hope all of the old people vote, that's great," Sanders said. "But I want young people to be voting at the same rates."

"We're taking on the corporate establishment. We're taking on the political establishment," Sanders said to boos on Monday, as he drew a series of differences with Biden from their time as colleagues in the U.S. Senate.

"Joe Biden voted for the war in Iraq. I voted against the war in Iraq," Sanders said to more boos.

"Joe Biden voted for the Wall Street bailout. I helped lead the effort against the Wall Street bailout," Sanders continued.

Four years ago, Sanders had magic in Michigan - but it wasn't clear that magic was going to be present again in 2020.

Michigan is the biggest prize on Tuesday with 125 delegates. Other states include Washington (89 delegates), Missouri (68), Mississippi (36), Idaho (20), and North Dakota (14).

Biden seems to be the favorite in Michigan, Mississippi and Missouri - and there have been polls showing strength in Washington.

"There is a flood of Biden +20 plus March 10-17 primary state polls that have come out in the past couple of days," tweeted political analyst Kyle Kondik.

The voters will have the last say.