When she ran for president the first time, Kamala Harris darted to the left as she fought for attention from the Democratic Party’s liberal wing.

After she dropped out, social and racial justice protests swept across the country in the summer of 2020, and Ms. Harris joined other Democrats in supporting progressive ideas during what appeared to be a national realignment on criminal justice.

One presidential cycle later, with Vice President Harris less than a week into another race for the White House, video clips of her old statements and interviews are being weaponized as Republicans aim to define her as a left-wing radical who is out of step with swing voters.

Former President Donald J. Trump is calling out her past positions and statements at his rallies, and on Monday his campaign began reserving time for television advertisements that are likely to resurface videos of Ms. Harris.

“The archive is deep,” said Brad Todd, a Republican strategist and ad maker who is working with David McCormick, the G.O.P. Senate candidate in Pennsylvania, among other campaigns. “We will run out of time before we run out of video clips of Kamala Harris saying wacky California liberal things. I’m just not sure that the rest of this campaign includes much besides that.”

The first television ads to attack Ms. Harris for her past statements came not from Mr. Trump’s campaign but from Mr. McCormick, who is challenging Senator Bob Casey.