Julian E. Zelizer: How Obama Makes His Case for a Second Term

Julian E. Zelizer is a professor of history and public affairs at Princeton University. He is the author of "Jimmy Carter," published by Times Books, and editor of a book assessing former President George W. Bush's administration, published by Princeton University Press.

In the coming year, President Obama must make the difficult transition from being the candidate who once ran as the maverick -- the agent of change -- to the candidate who now represents the political establishment. There is no way to escape this.

Rather than seeking to change the status quo, to some extent he must defend it to voters. The new message that he must craft for them is important, not just for re-election, but because it could help shape how he's perceived in the next four years, should he win.

Some presidents have had trouble making this transition.

Democrat Jimmy Carter, who masterfully campaigned in 1976 as the candidate voters could trust and who didn't engage in the kind of practices that had resulted in Watergate, didn't look so good in 1980 when he was the one holding the reins of power. Facing a troubled economy and foreign policy crises, Carter didn't have a strong response when Ronald Reagan lashed out against his record, claiming that the president was part of a system that had failed America.

Republican Ronald Reagan did much better running for his second term in 1984. Up against Democrat Walter Mondale, he was able to point to an economic recovery. It was Morning in America, his ad famously said. Reagan boasted that he was hawkish toward the Soviets, and was also reaching out to them.