Mr. Pence's attempt to recreate Mr. Trump as a conventional Republican also extended to foreign policy, as he sought to portray the president as a tough-minded leader.
"What we've seen with Donald Trump is that he has betrayed our friends and embraced dictators around the world," Ms. Harris said, citing the president's warm relationship with Russian president Vladimir V. Putin.
Mr. Pence ignored the accusation and instead cited the president's willingness to confront terrorists and a handful of foreign governments hostile to American interests.
"We've stood strong against those who would do us harm," he said.
In a familiar ritual for the vice president, Mr. Pence repeatedly spent precious debate minutes arguing that Mr. Trump did not say things that he plainly did. He falsely accused the media of selectively or inaccurately quoting the president on subjects ranging from a 2017 white-supremacist march in Charlottesville, Va., to American war dead to the president's remarks in a televised debate last week about a domestic extremist group.
As Ms. Harris called the economy "a complete disaster" Mr. Pence sought to shift attention from one of the most tragic years in the country's history and cast the debate forward.
"The American comeback is on the ballot," the vice president said, predicting that "2021 is going to be the biggest economic year in the history of the country."
And Mr. Pence warned that Mr. Biden would raise taxes, even momentarily breaking the civility of the evening by interrupting Ms. Harris to urge her to "tell the truth" about the Democrats' vow to repeal the Trump administration's tax overhaul.
The debate figured to be among the most symbolically consequential vice-presidential duels in recent memory, because of the age of both presidential candidates and Mr. Trump's Covid-19 illness. Either party's nominee would be the oldest man ever to take office, and Mr. Biden would turn 80 midway through a four-year term.
Yet in a political season overwhelmed by a daily torrent of news about a pandemic, a recession and the eruptions of a volatile president, it was not clear that an evening of conventional repartee between running mates had the potential to change the race in a significant way. So far, both Mr. Pence and Ms. Harris have been relegated to the margins of a contest between two of the best-known presidential nominees in modern times.
Mr. Trump seemed determined to keep it that way on Wednesday. He released a video in the afternoon assuring voters he was enjoying a rapid recovery and offering an infomercial-style testimonial about one of the drugs he has been prescribed. The president also churned out a deluge of tweets into the night, including one that called for the remaining American troops in Afghanistan to be "home by Christmas!"
In some respects, the low profiles of the two running mates are not surprising. Vice-presidential candidates typically enjoy a burst of publicity when they are selected before assuming their roles as understudies to the two nominees. But rarely has this dynamic been so pronounced as in this election, which features an incumbent who demands the spotlight each day and whose closest competitor for attention is a global health emergency.
The debate could also have long-term implications for a pair of running mates with presidential aspirations of their own. Mr. Pence is widely expected to pursue the Republican presidential nomination in 2024, whether or not Mr. Trump is re-elected; and if Mr. Biden is elected, Ms. Harris would most likely be seen as his heir apparent in 2024 or 2028, depending on whether he seeks a second term.