Early horse race presidential polls have an unimpressive track record in predicting the Democratic nominee. In fact, historical experience suggests there is money to be made betting against the current front-runners. As Associated Press reporter Will Lester explains:

...Edmund Muskie in 1972, George Wallace in 1976, Ted Kennedy in 1980, Gary Hart in 1988, Mario Cuomo in 1992 and Joe Lieberman in 2004 were early front-runners among Democrats. None won the nomination.

But, as poll analyst Mark Blumenthal notes in his Pollster.com article "Pew Center on Past Presidential Trial Heats":

...two of the four that did not win (Cuomo in 1991 and Hart in 1987) "withdrew from the race for reasons other than lagging support in the polls." So make of that history what you will.

And further, as Blumenthal quotes Pew Research Center's Nilanthi Samaranayake and Scott Keeter:

the increased front-loading of the primaries and the growing importance of early fundraising means that the dynamics of the nominating process are apt to be somewhat different this election cycle, making comparisons with past elections less useful.

True 'nuff. And there are two exceptions to the trend, as Lester notes:

Democrats nominated a former vice president, Walter Mondale, in 1984, and a sitting vice president, Al Gore, in 2000. For those elections, the early polls were more predictable at picking the front-runner.

Of course, we've never had a presidential spouse in early front-runner position before, much less the spouse of a popular President who had eight years of comparative peace and prosperity and who is a popular U.S. Senator. So don't go betting the ranch that Hillary will tank. But the point that early presidential trial heat polls have little predictive value for Dems is nonetheless worth keeping in mind.

Interestingly, the reverse is true for the GOP, says Lester:

Republicans have picked the early front-runner in seven of the past 10 elections, according to Gallup polling. In the other three elections, Republican incumbents cruised to re-election.

Lester offers a couple of possible explanations for this phenomenon. But could it be that Dems are just more open to change?

None of this is to say that early horse race polls have no value to Dems. They do help candidates identify areas of strength and weakness and who they need to challenge at various stages of the race. The thing to keep in mind is, the early polls help the candidates shape their message, persona and strategy, not those who want to predict the Democratic nominee.

For a peek at who the early "smart money", i.e. the gambling community, is actually betting on at this stage, check out the surprising current betting odds at Intrade's web pages.