Barack Obama was a 40-something fresh face when he won the presidency in 2008. He's gotten older in four years, but he was up against another older man -- Mitt Romney -- to keep his job.
But Hillary Clinton and Joe Biden -- two of the top potential Democratic replacements for Barack Obama four years from now -- will be either in or approaching their 70s when the next presidential election rolls around.
Smiling, jolly Biden sure did look like he could mount a campaign in a little under four years as he bounded along the inaugural parade route, hale and lively.
In an interview that aired on CNN today, Biden said he hasn't determined whether he'll seek the presidency in 2016.
"Oh there's a whole lot of reasons why I wouldn't run. I haven't made that decision and I don't have to make that decision for a while," Biden told CNN's Gloria Borger.
Asked if he's ready to run against Clinton in 2016, Biden said, "I haven't made that judgment and Hillary hasn't made that judgment."
"In a couple years, I think he's going to take a hard look at it," Beau Biden, the vice president's son and the attorney general of Delaware, said on MSNBC. "I hope he does."
Clinton, in her final days as secretary of state, says she needs a rest from public service and politics. But there isn't anybody who doesn't see her as one of Democrats' top contenders to replace Obama in 2016. She'd be the first woman president, but she'd also be one of the oldest.
She's the most traveled secretary of state in history and newly eligible for Medicare -- she turned 65 on Oct. 26. But Clinton, before a fall and treatment for a blood clot, could clearly still keep up with her younger staffers on whirlwind round-the-globe tours.
She'd be the same age as Ronald Reagan when he took office as the oldest first-termer in history. Biden, at 70 right now, would be the oldest newly elected president to take the oath of office at 74.
Nancy Pelosi bristled -- and maybe rightfully so -- when a 20-something reporter asked recently if she should step down as leader of House Democrats to make room for a younger generation.
"Let's for a moment honor it as a legitimate question," Pelosi said, chuckling. "Although it's quite offensive, although you don't realize it, I guess."
She said the question would never be asked for a man. But it is true that the top three Democrats in the House are all in their 70s. John Boehner, the top Republican in the country as speaker of the house, is 63. His two deputies are in their 40s.
Anecdotally, age could be a problem. Obama, after all, beat two older men. Bill Clinton beat three older men in presidential races if you count Ross Perot. But usually age is not the overriding issue in a campaign. Reagan actually scored points declaring at a debate with the younger Walter Mondale, "I am not going to exploit for political purposes my opponent's youth and inexperience."
We emailed the Yahoo! News columnist Jeff Greenfield, who has covered a lot of presidential campaigns, to weigh in.