It is difficult to think of any possible Democrat opponent who could best Mrs. Clinton for the nomination. A recent poll of likely Democratic voters in the important primary state of New Hampshire shows Mrs. Clinton with 64%, more than four times as much support as the next four names combined. True, it’s doubtful many people saw Barack Obama as a nomination threat in 2005, and it is possible some very strong candidates will emerge between now and 2016. But Mrs. Clinton starts with quite an advantage.

To keep that advantage, she must begin the process of increasing the number of Democrats who are politically indebted to her by campaigning and raising money for the party’s candidates for congress and governor. Her recent stumping on behalf of Terry McAuliffe, who’s running for Virginia governor, is certainly a start.

She needs to evaluate the shortfalls of her 2008 campaign and make sure she corrects them. She needs to start squeezing out any competition; if she lets word get around to liberal donors and party apparatchiks that she’s likely to run, that would suck much of the air out of other potential campaigns.