Biden vs. Trump 2020: Live Updates

With Mr. Biden building a steady advantage in the polls, a state that Mr. Trump won narrowly in 2016 threatens to move more firmly back into the Democratic column in 2020.

Since the end of June, Mr. Trump has spent more money on ads in 10 other states — with Michigan falling behind even much smaller states like Iowa and Nevada — and in recent days Mr. Trump’s campaign stopped buying ads in Michigan entirely.

The Biden campaign has more than tripled what Mr. Trump spent on television in Michigan in the last month, by far the most lopsided advantage of any swing state where both are advertising. And in Detroit, the state’s largest media market, the Trump campaign last ran a television ad, outside of national ad buys that include the state, on July 3, according to data from Advertising Analytics.

Mr. Trump faces a trifecta of troubles in Michigan, according to political strategists and state polling: reduced support among less educated white voters in a contest against Mr. Biden compared with Hillary Clinton; motivated Black voters in the state’s urban centers; and suburban voters who continue to flee Mr. Trump’s divisive brand of politics nationwide.

“Of all the states he won in 2016, Trump would be most hard-pressed to keep Michigan in his column this time around,” said Geoff Garin, a Democratic pollster for Priorities USA, a Democratic super PAC.