US elections: Could Kamala Harris be the first female president?

Already a trailblazer, Kamala Harris could be on the way to becoming the first woman to serve as president in the United States.

Biden announced Sunday that he was stepping aside after a disastrous debate performance catalyzed fears that the 81-year-old was too frail for a second term.

Moments after the announcement, he endorsed his vice-president Harris to replace him in the race.

If Harris becomes the Democratic nominee and defeats Republican candidate Donald Trump in November, she would be the first woman to serve as president.

Professor Barbara Perry, with the University of Virginia's Miller Center for Presidential Studies, told the Associated Press that the barriers Harris broke once being selected as Biden's running mate, could continue to fall. "Just as she broke barriers to become the first woman of color to serve as vice president," Perry said, "she would bring those characteristics to the top of the ticket of a major party, one of the two major parties."

Vice presidents are always in line to step into the top job if the president dies or is incapacitated. However, Harris has faced an unusual level of scrutiny because of Biden’s age. He was the oldest president in history, taking office at 78 and announcing his reelection bid at 80. Harris is 59.

"In presidential years, she's very youthful, and she certainly looks youthful and has a youthful energy and sparkle about her," Perry said.

Harris' nomination as the Democratic candidate is not a foregone conclusion, and there have been suggestions that the party should hold a lightning-fast “mini primary” to consider other candidates before its convention in Chicago next month.

Even before Biden's endorsement, Harris was widely viewed as the favorite to replace him on the ticket.

Perry believes gender, rather than race, may prove a bigger challenge for Harris. From time of George Washington, Perry said, there is a paternal model of presidents. "It's too important an office to exclude half of the American population," Perry believes.

Perry said Republicans are likely to reprise personal attacks against Harris that they used during the 2020 campaign.

So far, the closest a woman has got to the White House was in 2016 when Hilary Clinton narrowly lost to Donald Trump in the race to the White House.

Harris could offer up a strong contrast to Donald Trump and his running mate J.D. Vance. In contrast to the two men, Harris, who is a leader on abortion rights, could attract younger, more progressive voters.