How much does experience matter to voters? Not much, if the recent past is any guide. How much experience did Jimmy Carter, Ronald Reagan, Bill Clinton, and George W. Bush have in foreign affairs prior to becoming president? None. How much would Barack Obama have? Less than a little. Democratic primary voters seemed not to have cared about Barack Obama's lack of experience, Hillary Clinton's main charge against him. They supported Obama for other reasons. McCain's selection of Sarah Palin has ushered in a great rhetorical reversal: Suddenly Democrats are attacking Palin for a lack of experience, something they cared little about when it was Obama who was inexperienced. Now it matters a great deal to them, apparently. And it is now Republicans who are arguing in behalf of change - a fresh voice, a historical milestone, the future of conservatism, and so on. Change worked - and is working - for Obama. Now McCain wants it to work for him.