As the days wore on, Mr. Trump took aim at news organizations and demanded the resignation of Democrats like Mr. Schiff, whom he accused of lying repeatedly in discussing potential collusion between Mr. Trump and the Russians.
In a warm-up rally more than an hour before Mr. Trump arrived, Laura Cox, the chairwoman of the Michigan Republican Party, led the crowd in chants of “No Collusion! No Obstruction!” The crowd also chanted “Lock her up!” after Ms. Cox denounced Mrs. Clinton for counting Harvey Weinstein as one of her supporters.
On the flight to Grand Rapids, Corey Lewandowski and David Bossie, two former campaign advisers known for riling up Mr. Trump on Air Force One before his rallies, were aboard.
Inside the White House, aides were concerned about the two of them tagging along — and possibly having open access to the president — but ultimately did not take steps to limit their travel, according to a person familiar with the planning.
Mr. Trump has long savored his victory in Michigan. But the state could be more of an uphill struggle in 2020. Democrats made significant gains in the 2018 midterm elections, including winning the governorship.
General Motors, one of Michigan’s key employers, has laid off workers, despite Mr. Trump’s efforts to pressure the carmaker to expand manufacturing in the United States. He also faces headwinds in winning congressional passage of the retooled version of the North American Free Trade Agreement, which he has promoted as benefiting workers in Michigan.
Inside the arena, however, Mr. Trump’s supporters basked in the glow of the president’s claims of vindication and expressed indignation on his behalf at the proliferating investigations into him and his administration.
“He went through so much persecution,” said Brenda Freye, a medical assistant from nearby Muskegon, who recalled attending his campaign rally here in November 2016. “They were so unfair to him.”