“The fact that Trump is having to spend time in Grand Rapids in that media market shows you how difficult it is for a Republican to win Michigan,” said Jeff Timmer, another GOP consultant in the state. “Doing it again is not going to be impossible, but it’s going to be an uphill battle.”

“The planets have to align just so, like they did for the president in 2016 when he won by 10,000 votes,” Timmer said.

Republicans were largely able to maintain Trump’s gains in Ohio in the 2018 election, but in other key rust belt states he carried in 2016 — Wisconsin, Michigan, and Pennsylvania — they lost every statewide contest on the ballot and watched Democrats make gains in suburban districts.