Will Joe run? That's Vice President Joe Biden, of course, and that's been the topic in Washington this week as he's publicly flirted with the idea.
If Mr. Biden decides to run, the most difficult task for him may come in cobbling together a coalition capable of challenging Democratic front-runner Hillary Clinton. Much has been made of Mrs. Clinton's struggles in recent weeks - stories about her personal email server and expensive vacation in the Hamptons - but she still sits in a very strong position among the Democratic electorate.
In short, the divides that defined the Democratic primaries in 2008, the last time there was no incumbent running, simply aren't apparent in the 2015 - at least not yet.
Related: Some voters doubtful Biden will run
President Barack Obama rode to the nomination on a mix of African-American and liberal Democratic primary voters.
Currently those groups are locked pretty securely in Hillary Clinton's camp along with the groups that backed her candidacy in 2008 - whites and moderate/conservative primary voters.
For all of Mrs. Clinton's troubles, she has a pretty unified party behind her right now. This past week's poll from Quinnipiac also showed Mrs. Clinton leading across the Democratic ideological spectrum.
In other words, for Mr. Biden to really shake up the race he would need to do more than find voters, he would need to transform the race more fundamentally. And that is not easy, particularly when he would have a lot of money to raise and a lot of endorsements to seek, all with September rapidly approaching
There is still a long way until the first primary vote is cast, of course, but the better parallel for the 2015 Democratic race may be 2000, when there was one clear front-runner, Al Gore, and one serious challenger, former Sen. New Jersey Bill Bradley.
The summer of 2000, Mr. Bradley had a moment when he got a bump in the polls, climbing at the expense of Mr. Gore. But in the end, he was never a serious threat to Mr. Gore's nomination.
The question for Mr. Biden is could his entry fundamentally change the 2016 equation and shift us from a 2000 storyline to a 2008 narrative. The numbers suggest it would be a very difficult road.
This story originally appeared on NBCNews.com