If Joe Biden wins a second term, Kamala Harris will again find herself a heartbeat away from the presidency. The only difference: this time it will be an 82-year-old heart.

Vice presidents are often an afterthought in Washington, but with Biden smashing previous age records in the Oval Office, the three-decades-younger Harris will go into the election under searing scrutiny.

If anyone needed a reminder how much Harris could matter one day, they got it in November 2021, when Biden went under anesthesia for a routine colonoscopy. The procedure was quick but for those 85 minutes, the United States had its first female acting president.

Biden, 80, is broadly in good health, according to his doctor, and eager to remain commander in chief. However, if he wins reelection in 2024, he will be 82 by the time he swears the oath of office and 86 when he steps down.

Harris, 58, has already brought a wind of change to the White House. She’s not only the first woman ever in the job but the second person after Barack Obama to hold either of the top two executive spots who was not white.

But despite — or some say because of — that trailblazing achievement, Harris has polarized Americans.

– Glass ceiling –

In 2020, Harris wanted the presidency herself.

After a strong campaign launch, notable for a stinging attack on Biden during a debate, she floundered in the polls. As Biden’s running mate, however, she consolidated a coalition leaning heavily on Black voters and so helped defeat the disgraced incumbent Donald Trump.

Already having served as California’s first Black attorney general and the first woman of South Asian heritage elected to the US Senate, she sports a dizzying CV.

Critics say she has been underwhelming in the White House.

The vice presidency has been known to flummox many office holders — perhaps most famously Franklin D. Roosevelt’s deputy, John Garner, who summarized the job as “not worth a bucket of warm piss.”

A rare vice presidential task — acting as tie breaker for the president’s party when the Senate is split 50-50 — became a core part of Harris’ existence in the two years where the upper chamber was evenly divided.

So although her role was essentially a formality, all those 51st votes she cast put her at the center of what even opponents had to concede was Biden’s startlingly productive first term.

– Finding her feet –

An unusually high staff turnover fed rumors of discontent in the vice presidential office. A December 2021 Washington Post article quoted anonymous sources complaining of a “soul destroying” atmosphere.

Harris was also struggling to win the public relations battle in her policy work.

Tasked by Biden with getting to the roots of the illegal migration problem on the Mexico border, she visited Central America. However, she was powerless to address the immediate problem of what the administration conceded was a “broken” immigration system — something Congress would need to tackle.

As press coverage soured, supporters argued that Harris was being held to unfair standards as a woman and an ethnic minority member.

It didn’t help that she had a penchant for word salads and the occasional gaffe — including accidentally saying during a 2022 visit to the Korean peninsula’s heavily fortified DMZ border that the United States valued its alliance with the communist North, instead of the South.

By the middle of Biden’s first term, Harris was gradually finding her feet.

A spate of high-profile foreign trips, including meeting Chinese leader Xi Jinping and representing the United States at a regional Asia-Pacific summit, gave her valuable exposure in case she should find herself in the main job one day.

In February this year, it was Harris whom the administration sent to the Munich Security Conference and for the first time declare that Russia had committed “crimes against humanity” in Ukraine. She got positive headlines for a March trip to Africa where she showed her emotional side while visiting a former slaving center in Ghana.

Back home, she also became a prominent voice in the administration’s pushback after the Supreme Court scrapped federal protections for abortion rights. The issue ended up helping Democrats to stun the Republicans and keep losses to a minimum in the November 2022 midterm elections.

Win or lose in 2024, Harris will be remembered for having broken the second highest glass ceiling in US politics.

There’ll also be her husband, Doug Emhoff. He’ll forever have the honor of being the first Second Gentleman of the United States — or as the slightly awkward acronym goes: SGOTUS.