Jacob S. Hacker is Professor of Political Science and Co-Director of the Center for Health, Economic, and Family Security at U.C. Berkeley. He is also a Fellow at the New America Foundation in Washington D.C.  His most recent books are Health At Risk: America's Ailing Health System--And How to Heal It, and The Great Risk Shift: The New Economic Insecurity and the Decline of the American Dream.

To my eyes and ears, Obama destroyed McCain on substance as well as style last night. Obama had clear substantive answers to every question, he seemed calm and measured, and his closing statement was as devastating as McCain's was rambling. Sure, he took a few liberties with the facts--even his own campaign is saying that the average family will save $2,500 in total from his health plan, not $2,500 in premiums alone--but this was a confident debate performance in which Obama again and again reached out to independents with a call for a new kind of politics and drove home his advantage on economic policy.

McCain, on the other hand, really had a disastrous performance. Even if he hadn't looked as if he were undergoing some kind of strange, recurrent seizure, he threw out his points in staccato fire without pausing or linking them together. On substance, he didn't know the basics of Obama's health and tax plans after three debates, leaving himself open to looking ill-informed. McCain was very strong in the first debate, on his favored foreign-policy ground, but his performances have steadily degenerated since. This was his worst--and it's the final nail in an already tightly sealed coffin.

By the way, we political scientists generally subscribe to the "minimal effects" view of campaigns, in which both sides are savvy enough that their efforts cancel each other out. And this certainly seems like an election in which the fundamentals have swamped any campaign strategies either side has used. But I think it's time to recognize that Obama has done something more profound in this cycle than simply run a smart campaign; he is showing that the old Republican strategy on economic policy of calling for tax cuts and criticizing government, while thowing mud in every other area, has real limits when the other side directly confronts it with arguments for "investment" and more carefully targeted tax policies.

We can only hope that it really is the end of the Karl Rove era in American politics. It's certainly the end of John McCain's campaign.

--Jacob S. Hacker