By Byron York

An article in Politico got a lot of buzz in Washington, D.C., by reporting that Sen. Kamala Harris might not be a very strong front-runner, or even a front-runner at all, in the Democratic vice presidential selection race.

Politico reported that 76-year-old former Sen. Chris Dodd, a member of 77-year-old former Sen. Joe Biden’s VP selection committee, was unhappy that Harris showed “no remorse” for her rough attacks on Biden during the Democratic presidential primary season.

But the report revealed something else which should have gotten more attention. An unnamed Biden adviser told Politico that the VP choice is being shaped by the possibility that Biden might serve just one term.

“If you assume Biden isn’t going to run for reelection, you don’t want someone who is only paying attention to 2024,” the anonymous Biden adviser said. “The decisions that need to be made are not going to be easy. Biden’s vice president might want to dodge a lot of tough issues if they only have an eye on 2024.”

And why might Biden serve just one term? Because if elected, he would be by far the oldest president ever to begin his time in the White House. Biden will be 78 years old on Inauguration Day, older than President Trump, who took the oath of office at age 70. If Trump were to win re-election and serve a full second term, he would retire at the same age, 78, that Biden would be upon beginning his presidency.

The previous oldest? Ronald Reagan left office at 77 after two terms in office — younger than Biden would be on day one of his presidency. And Reagan’s second term was filled with speculation that he had suffered mental decline and wasn’t the man he used to be.

There’s an implicit sense, when a candidate runs for president, that he or she will want to serve two terms if elected. That way, the president is not a lame duck upon taking office. But with Biden, that would be asking the American people to serve in the White House until age 86, which is far beyond anything that has ever happened in American politics.

And the fact is, Biden, at 77, has clearly slowed down. He does not appear to be as vigorous as he was during his 44 years in the federal government. Trump slams him mercilessly for it, something which will likely increase as the campaign goes on.

It’s extraordinary that the presidential race has come down to two candidates in their 70s. Trump was the oldest ever to take office for his first term. Democrats had two dozen candidates, most of whom were in their 40s, 50s and 60s — prime ages for a president. Yet they chose one significantly older than the Republican Trump.

At the moment, Biden is facing very little commentary and criticism about his age. There was more discussion of age when Republican John McCain, who would have been 72 had he been elected, ran in 2008, and when Republican Bob Dole, who would have been 73, ran in 1996. But Biden, who would be 78, attracts less talk.

But that is why the vice presidential decision is particularly complex. Bluntly put, Biden does not appear ready to tackle the world’s toughest job until the age of 86. And if he is not, it is extraordinarily important for Democrats to have a vice president who can run to succeed a one-term Biden. As the anonymous Biden adviser suggested, that complicates things. Would the vice president be running for president the moment she takes office? What would that mean? Biden’s age is an important factor in the 2020 race, even if some commentators don’t want to talk about it.

Byron York is chief political correspondent for The Washington Examiner.