But Mr. Biden, the Democratic nominee, also expressed solidarity with peaceful protesters, denounced systemic racism and said he had spoken with the parents and other relatives of Mr. Blake, a Black man whose shooting by a white police officer touched off the protests.
“I told them justice must and will be done,” Mr. Biden, speaking in a video that was posted on social media, said of his discussions with Mr. Blake’s family members. He also urged those listening to his remarks to “put yourself in the shoes of every Black father and Black mother in this country and ask, ‘Is this what we want America to be?’”
Mr. Biden, the Democratic nominee, is confronting competing political pressures. While many Americans, including progressive Democrats, overwhelmingly support protests against racial injustice and police brutality, Mr. Trump has tried to cast his rival as a radical who would diminish or even eliminate police agencies, and unleash a wave of lawlessness.
Mr. Biden was emphatic in criticizing those who were not protesting peacefully.
“As I said after George Floyd’s murder, protesting brutality is a right and absolutely necessary,” he said. “Burning down communities is not protest, it’s needless violence. Violence that endangers lives. Violence that guts businesses, and shutters businesses, that serve the community. That’s wrong.”
Mr. Biden’s response to the events unfolding in Kenosha is his latest balancing act on law enforcement matters. His deep involvement in the 1994 crime bill, for example, has earned him skeptics among those who are focused on criminal justice reform.
On the flip side, the Trump campaign has repeatedly, and falsely, accused Mr. Biden of seeking to defund the police, a measure that he opposes. Despite being untrue, the claim could hurt him, especially in swing states like Wisconsin, if Republicans are able to make it stick.