Interviews with two dozen Biden voters across the country found near unanimity that it was important for the Senate, the Justice Department and state prosecutors to aggressively pursue Mr. Trump, his family members and top aides — holding them accountable well beyond the impeachment charge against the president for inciting the Capitol riot on Jan. 6. The consensus cut across differences of ideology, income, race and sex.

“He’s a crook and he needs to pay for the crimes he’s done,” said Teresa Steele, a Republican in Denton County, Texas, who voted for Mr. Biden…

Democratic voters vehemently rejected the idea that by aggressively pursuing Mr. Trump, Mr. Biden would sacrifice political capital or impede the country from unifying, a theme of his campaign.

“I can’t help but cringe when I hear Republicans calling for unity,” said Laura Gutknecht, 67, an engineer at a radio station in Madison, Wis. “Now, unity? It’s very hard to take them seriously. They’ve done nothing to unite the country, unless it’s uniting against this person or that group.”