Will voters split their tickets?

Americans like divided government. Clinton and the Democrats only ruled together for two years; Ronald Reagan had to share power with the Democrats for his entire “revolutionary” term. The Bush years were exceptional in that the GOP held both the White House and Congress for four years; it would have been six but for the Jim Jeffords defection. The other four years were terms that followed the start of new wars, which may account for the exception.

Many of the polls that currently show Barack Obama leading by a significant margin are weighted to reflect party affiliation. That is, pollsters figure out what percentage of their sample is Democrat, Republican or independent. They use these estimates to extrapolate the results of their telephone polls (which sample 0.001% of registered or likely voters, at best) to the entire country. Right now, for instance, Rasmussen weights Democrats at 39.3% and Republicans at 33.0% of its sample.

This difference–6.3%–all but wipes out the 7-point difference between Barack Obama and John McCain in Rasmussen’s daily tracking poll. I’m not saying that Rasmussen is spinning its results–I think it’s been one of the more reputable polling agencies, and certainly less volatile than many of its competitors. I just think they may have missed something potentially important.

The Republican brand is really off right now. But the McCain brand is not–nor is the Palin brand, despite desperate attempts by the media to sink her. I think it is entirely possible that voters will split their tickets in this election. They might take their revenge (justified or not) on Republicans by voting Pelosi & Reid back into legislative power, while denying Obama the levers of executive power.

This might sound a little far-fetched, given the worrying trend in the polls lately. But remember, the only poll that counts is the one in the ballot box at the end of Election Day. And this may be one of those “Dewey Defeats Truman” moments, where McCain pulls off the upset. He’s certainly done it before. America is fed up with Bush but is not sold on Obama. And there’s not much Obama can do to change that. McCain’s task is tough, but if the polls have been hiding the split-ticket possibility, Obama’s task may be even tougher.