Everyone knows the market hates uncertainty. In a presidential election year volatility is supposed to be driven by doubt as to who will win the White House, not on whether the global financial system will collapse and we'll all return to the barter system.

The Bush administration's proposed $700 billion bailout and the specter of another Great Depression has wrested the market's attention and put the public's focus squarely on the state of the economy. The latest Washington Post/ABC News and Wall Street Journal/NBC News polls show this gives a clear advantage to Sen. Barack Obama (D-Ill.), no?

Well, not exactly. Polls, it turns out, say a lot of things. (See chart below.) The only clear takeaway for investors is that trading on the endless stream of presidential polling data is a sucker's game.

In the Journal/NBC News poll, for example, voters said Obama would be better at handling a range of economic problems, and that the economy is at the forefront of their concerns. At the same time (and one would think contradictorily), the data showed that the two candidates, Obama and Sen. John McCain (R-Ariz.), are still essentially tied in the race for the White House.

As the Journal put it: "The poll showed that neither candidate had yet turned the crisis to their advantage: 48% said they'd vote for Sen. Obama if the election were held now, compared with 46% for Sen. McCain." (The poll's margin of error makes it a dead heat.)

Then comes perhaps the biggest kicker: The same poll conducted before everything blew up and the market cratered offered virtually the same results. The more things change

For now the market is moving on the progress of the proposed bailout, the outcome and consequences of which are uncertain enough. Put that against the background of a presidential election that is still five long, fluid weeks away and it's just foolish to try and play the outcome.

After all, historically a tight presidential race causes plenty of volatility all by itself, notes Jeffrey Kleintop, chief market strategist at LPL Financial. Markets typically pull back during the summer of a presidential election year and remain volatile until the election uncertainty fades. "For markets, what matters most isn't about getting 'out of the woods'; it's about knowing how big the forest is," Kleintop wrote Monday.

Volatility is not your friend. It is risk. It increases the odds that you will buy high and sell low. Besides, all that maneuvering is likely to be for naught, anyway, since the link between presidents and stock returns is dubious at best.

Then there's the argument that markets don't move on the polling data in the first place. Barry Ritholtz, chief executive and head of research at Fusion IQ, has said this repeatedly and persuasively. Either way, the lesson is the same. Buy and hold, and ignore the polls.