Governors and other officials reacted angrily to the president’s moves, calling it a election-year ploy as they squared off over crime, civil liberties and local control that has spread from Portland, Ore., across the country.

With military-clad agents already sweeping through the streets of Portland, more units were poised to head to Chicago, and Mr. Trump suggested that he would follow suit in New York, Philadelphia, Detroit and other urban centers. Governors and other officials compared his actions to authoritarianism and vowed to pursue legislation or lawsuits to stop him…

The president portrayed the nation’s cities as out of control. “Look at what’s going on — all run by Democrats, all run by very liberal Democrats. All run, really, by radical left,” Mr. Trump said. He added: “If Biden got in, that would be true for the country. The whole country would go to hell. And we’re not going to let it go to hell.”

Democrats said the president was the one out of control. Senator Jeff Merkley of Oregon said he would introduce legislation to limit the role of federal agents in cities like Portland. “This isn’t just an Oregon crisis,” he said. “It’s an American crisis. We need to stop Trump before this spreads.”