The president defied requests from local leaders to stay away from Kenosha as he arrived on Tuesday morning to offering support for law enforcement.
Before boarding Airforce One to visit the city, Mr Trump took aim at mayor John Antaramian as he continues to point fingers at local Democrats for the ongoing civil unrest in US cities.
“I think a lot of people are looking at what’s happening to these Democrat-run cities and they’re disgusted,” the president said.
“They see what’s going on and they can’t believe what’s taking place in our country. I can’t believe it either.”
He cited reports that protesters had tried to break into Mr Antaramian’s house.
“I saw last night where these radical anarchists are trying to get into the mayor’s house and lots of bad things were happening to this poor foolish, very stupid mayor. I mean how he can be mayor I have no idea,” he said.
“They had tremendous numbers of people really harassing him horribly and I guess trying to break into his house and he still sticks up for them because he’s a fool. Only a fool would stick up for them like that.”
With the United States polarised over issues of racial injustice and police use of force, Mr Trump is appealing to his base of white supporters with a “law and order” message as opinion polls show him narrowing the lead of his Democratic rival, former vice president Joe Biden.
Wisconsin is a political battleground state that the Republican Trump won narrowly in 2016. He badly needs to keep the state in his column as he seeks re-election on November 3.
The president visited a burnt-out furniture store that was destroyed in the upheaval and then a makeshift command centre to praise National Guard troops who are reinforcing local police.
“This ended within an hour,” Mr Trump said, referring to the relative peace that followed the arrival of federal law enforcement officers.
“You have to be decisive, you have to be tough, and you have to be strong. And you have to be willing to bring people in,” He added.
The state’s Democratic governor and the city’s Democratic mayor both urged Mr Trump to avoid Kenosha to prevent inflaming tensions and allow citizens to heal, but the president dismissed their appeals in order to show support for law enforcement and business owners whose stores were looted and set ablaze.
Mr Trump has sought to blame Democrats, calling them soft on the violence and property damage that has broken out at anti-racism protests since George Floyd’s death in Minneapolis died on May 25.
The country was still reckoning with that case when a white officer in Kenosha fired seven shots at the back of Jacob Blake, 29, as he entered his car on August 23.
Kenosha has become one of the flashpoint cities where anti-racist demonstrators have clashed with Trump supporters who have converged on protest sites, sometimes openly carrying arms while vowing to protect property from looters.
A 17-year-old Trump supporter has been charged with killing two people and wounding another with a semi-automatic rifle in Kenosha.
Mr Trump defended the white teenager, who faces six criminal counts, and declined to condemn violence from his supporters.
But in Portland, Oregon, site of three months of nightly protests that have often turned violent, a Trump supporter was shot dead on Saturday and the president lamented that “they executed a man in the street.”
Kellyanne Conway, a Trump adviser until Monday, said last week the president stood to benefit politically from the kind of unrest that erupted in Kenosha.