Vice President JD Vance downplayed the significance of the Watergate scandal during a speech on Thursday, saying that the controversy that toppled President Richard M. Nixon would be “like a 12-hour news story” if it happened today. i

“The idea that it would have taken down a presidency is crazy,” Mr. Vance added, saying he had been joking backstage about the scandal before his appearance at the Richard Nixon Presidential Library and Museum in Yorba Linda, Calif.

Mr. Vance, who is widely seen as a potential 2028 presidential contender, compared himself to Nixon, who resigned in disgrace after his administration tried to cover up its involvement in a break-in at the Democratic National Committee headquarters.

“Young senator, vice president, writes some best-selling books, is hated by the media,” Mr. Vance said. “It kind of sounds like JD Vance. I’ve always liked Richard Nixon.”

Mr. Vance also conspiratorially compared the political forces that pushed Nixon out of office to President Trump’s opponents.

“If you look at the story of how the deep state took down Richard Nixon,” Mr. Vance said, “it’s not all that different from what the same groups of people, the same institutions, tried to do to Donald Trump in the first Trump administration.”

Mr. Vance’s remarks were notable in part because of how Mr. Trump and his administration have pushed to expand presidential power and test the boundaries of the law. Mr. Vance, a critic of Mr. Trump’s during his first presidential bid in 2016, has become a fierce loyalist and stood by the president through many controversies, casting him as the victim of an unjust political system.

The vice president’s defense of Nixon followed a similar playbook, seeking to rewrite the historical narrative of a scandal-scarred president so that he becomes the target of a witch hunt instead of the perpetrator of wrongdoing.

A spokesman for Mr. Vance did not immediately respond to a request for comment.

Mr. Vance was in California in part to promote his new memoir, “Communion: Finding My Way Back to Faith” and in part to raise money for the Republican Party.

After his talk at the library, Mr. Vance raised $4.2 million at a Republican National Committee dinner in Palo Alto, according to a person briefed on the event who spoke on the condition of anonymity to describe the private gathering.

Mr. Vance is the first vice president to serve as the finance chair of the R.N.C. In that role, he courts donors who could prove helpful if he decides to run for president.

At the Palo Alto dinner, which was earlier reported by Axios, supporters each paid $250,000.