The Republican mayor of Michigan's fourth-largest city is throwing his support behind Joe Biden as the former vice president seeks to build on his momentum following his sweep of most states on Super Tuesday.

Sterling Heights Mayor Michael Taylor will on Tuesday vote for Biden in the state's presidential primary, marking the first time he has voted for a Democrat, according to the Chicago Tribune.

"How could I look at those three kids and tell them I'm proud to support Donald Trump? I can't. I won't. I'm voting for @JoeBiden tomorrow and endorsing him for President of the United States. I hope you'll join me," Taylor tweeted Monday.

How could I look at those three kids and tell them I'm proud to support Donald Trump? I can't. I won't. I'm voting for @JoeBiden tomorrow and endorsing him for President of the United States. I hope you'll join me. #Biden2020#MichiganPrimary https://t.co/GIA3PT5DNS — Michael C. Taylor (@MayorMikeTaylor) March 9, 2020

The mayor, who was elected in 2014, first shared his endorsement of Biden with the Chicago Tribune. He called President Trump's presidency "deranged" and said Biden is best positioned to build the broad coalition of voters needed to win the White House in November.

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"I think Joe Biden is the candidate who can unify all of the Democrats, and he's the candidate who can appeal to moderates and Republicans like me who don't want to see four more years of President Trump," Taylor told the Chicago Tribune.

Michigan is one of six states where voters are hitting the polls Tuesday for their respective primaries. The state will be key for Democrats as they seek to make Mr. Trump a one-term president in November and is the biggest prize of the day with 125 delegates up for grabs.

Bernie Sanders snagged a surprise upset against Hillary Clinton in the state's Democratic primary in 2016, though a Monmouth University poll released Monday shows Biden has a 15-point lead over the Vermont senator. In 2016, however, Sanders trailed Clinton by double digits heading into Michigan's primary.

Macomb County, where Sterling Heights is located, is one of 12 Michigan counties that went for President Obama in 2008 and 2012 but was won by Mr. Trump in 2016, the first time a Republican won the state since 1988. In addition to Michigan, Wisconsin and Pennsylvania, states the president also won in 2016, are crucial battleground states for Democrats in this year's general election.

Biden has racked up key endorsements heading into Tuesday's primaries, including from former Democratic presidential candidates Cory Booker and Kamala Harris, and Michigan Governor Gretchen Whitmer. The three appeared at a campaign rally with Biden in Detroit on Monday.