This guy says yes. Allan J. Lichtman, a political scientist at American University in DC, a Harvard grad, and author of the book "The Thirteen Keys to the White House" wrote this on Oct 4th, 2007:
The election for president is more than a year away. Neither major party has as yet chosen a nominee. Yet the results of the 2008 election are already in: the Democrats will recapture the White House next fall, whether they nominate Hillary Rodham Clinton or Barack Obama, John Edwards, or Bill Richardson. Only an unprecedented cataclysmic change in American politics during the next year could salvage Republican hopes.
http://www.britannica.com/blogs/2007/10/the-13-keys-to-the-white-house-why-the-democrats-will-winInstead of things like daily tracking polls, he believes far more fundamental keys determine elections, and short of radical shifts or missteps, Presidential elections are often determined well before election day. This system has correctly accounted for every election since 1860, in terms of the popular vote. As he notes, not since 1888 has the popular vote diverged from the electoral, except in 2000, and he says point blank that it was because of theft (he has extensive involvement in the purging of black voter rolls issue, having assisted the US Commision on Civil Rights).