Hillary Clinton for president? Eight Democrats who might run next time.

In this March 15 file photo, Vice President Joe Biden speaks at a union hall in Toledo, Ohio. (Madalyn Ruggiero/AP/File)

2. Joe Biden

If Mr. Obama heads into his final stretch in office with a decent economy and no major liabilities abroad, then Vice President Joe Biden could be in a position to claim Obama’s “third term” – especially if Mrs. Clinton doesn’t run.

For more than a year, Mr. Biden has dropped hints about 2016. On Election Day, while waiting in line to vote in his home state of Delaware, he was asked if this was the last time he’ll vote for himself. He smiled: “No, I don’t think so.” At another point he joked about running for “county council or something.”

“I’m probably in the best shape I’ve been in my life,” Biden told CNN in October 2011, when asked about 2016. “I’m doing pretty well, I’m enjoying what I’m doing, and as long as I do, I’m going to continue doing it.”

One issue might be age. Biden will be in his mid-70s in 2016. If he runs, he’d be angling to be the oldest person ever elected president.

Biden has been a Washington fixture since his first election to the Senate in 1972 – and he’s run for president twice before. By 2015, when the field starts to form, Democrats may be looking to their next generation for presidential candidates.