“You can observe a lot by watching,” as the late, great Yogi Berra once said. And for a certain vice president with his own Berra-like penchant for mangled English, watching the headlines has to be enticing.

"Biden surges in new Bloomberg poll," says Politico. "Investigators find emails Hillary Clinton said were erased," reports the New York Times. "Top unions put brakes on Hillary endorsement," reads another. It all cries "opportunity!"

Yet Joe Biden, a lifelong politician with a lifelong ambition to be president, still waits. He knows that the aura of invincibility that once protected Clinton has been shattered, just as it was in 2008. He has also been reminded far too often -- and far too recently -- that our time on this planet is limited and can be snatched away at any moment.  In November he'll turn 73, and while it ain't over 'til it's over, after the 2016 cycle it's over for him. The future ain't what it used to be.

Yet still Biden wavers, and political pragmatism has to be part of it.  He would enter the race as an underdog, without the organizational or fundraising support of the Clinton machine. Poll numbers that look good while you sit on the sidelines have a way of turning sour once you actually enter the arena. And while Biden is a respected figure in Washington, his previous bids for the presidency have not exactly created a firestorm of support outside the Beltway.

But as Biden has also made clear, much of his hesitancy is personal in nature, a consequence of the recent death of his son Beau from brain cancer. Before his death, Beau had pressed his father to run, but for the elder Biden the process of mourning and healing is far from complete.

"It comes or it doesn't," he said in a recent interview. "I've just got to be certain that if I do this, I'm able to look you in the eye and everyone else and say I'm giving all my passion, all my, all my energy and will not be distracted. And secondly, equally as important, the other piece is: Is this moment, is this the best thing for the family as a unit?"

Nobody can answer those questions for him, but he's thinking about them the right way. He can't ask others to make a commitment to his cause that he himself hasn't made fully. Earlier, there was talk that Biden might announce that he would be running for only one term, but that's the kind of half-measure and half-commitment that would probably doom a candidacy. You're in, or you're out. When you come to the fork in the road, take it.

Private concerns aside, I do think that a Biden candidacy would be a good thing for the Democratic Party, and probably a good thing for Hillary Clinton as well. The competition would force her out of her comfort zone, which has proved a dangerous place for her. And a three-way race among Biden, Clinton and Bernie Sanders would give the media something to cover on the Democratic side other than the email controversy. (An earlier start to the Democratic debate schedule would help for the same reason.)

Biden acknowledges that the longer he waits, the more difficult a campaign becomes. Put another way, it gets late early in politics.

"We're just not there yet," he said in the interview cited above, "and may not get there in time to make it feasible to be able to run and succeed because there are certain windows that will close. But if that's it, that's it. But it's not like I can rush it."

Personally, and largely out of respect for Biden, I hope he chooses not to run. Because, and to quote my favorite political philosopher one more time, “If you don’t know where you are going, you might wind up someplace else.”