Vice President Mike Pence, addressing the Republican National Convention on Wednesday, rejected allegations of endemic police racism and painted the protests as a threat to Americans, condemning "the violence and chaos engulfing cities across this country".
Mr Pence accused President Donald Trump's election rival Joe Biden of supporting action that had led to the unrest and attacks on police.
"Joe Biden would double down on the very policies that are leading to unsafe streets and violence in America's cities," he said.
March on Washington
Players in the NBA and WNBA, the women's pro basketball league, forced the postponement of playoff games Wednesday after the Milwaukee Bucks, whose home base is close to Kenosha, walked out.
"Despite the overwhelming plea for change, there has been no action, so our focus today cannot be on basketball," Bucks players said in a statement.
The Milwaukee baseball team, the Brewers, also refused to play while the US Major League Soccer called off five games and the pro tennis ATP/WTA circuit declared a halt to play for Thursday.
Meanwhile rights activists Al Sharpton and Martin Luther King III, along with other civic leaders and the families of Jacob Blake and other black victims of police violence announced a "Commitment March: Get Your Knee Off Our Necks" protest in Washington for Friday.
FBI opens investigation
Activists continued to demand action against the Kenosha police officer who shot Jacob Blake, 29, in the back several times on Sunday as Blake tried to enter his car, with his three sons watching.
On Wednesday, the Wisconsin Department of Justice named the officer as seven-year Kenosha force veteran Rusten Sheskey.
Officials said police were attempting to arrest Mr Blake, though not specifying any charges, and that an attempt to tase him had failed. They added that a knife had been found in his car.
The federal Department of Justice meanwhile announced an FBI civil rights investigation into Mr Blake's shooting, which has left him paralysed from waist-down.
Meanwhile Illinois police were preparing to extradite to Kenosha 17-year-old Kyle Rittenhouse, who was detained on charges of first degree murder in relation to the shooting of protesters on Tuesday night.
'We are targets'
Late on Wednesday in Kenosha protestors said they were determined to keep marching for justice and police reform.
"We are targets. I'm big and black, they see me as an enemy all the time, everywhere I go," said a musician who goes by the name Big Homie Trail.
"Everybody's expecting us to go out all rage, to go crazy, in the fourth night but we are doing a peaceful protest as we are supposed to do," he added.
"We're going to keep marching, they are trying to shut us down, but they won't."
People spoke warmly of the two protesters, both white, who were shot dead.
A young woman, who would not be identified, paid tribute to Anthony Huber, a 26-year-old who was killed trying to stop the gunman with his skateboard.
"He was sweet and now he's dead. He had nothing but love in his heart for this city, that's why he was here last night," she said.