When to Drop Out?

How does a Democratic candidate know it's time to quit? Common indicators like low funds, indifferent press, and fading support may not apply in this year's race, where both hopefuls have enough of all three to last to the convention. Instead, one may quit when fighting on hurts that candidate’s political future, writes John Dickerson in the Washington Post.

Otherwise, why would Barack Obama or Hillary Clinton drop out? Both want their supporters and pet causes to keep thriving. And either may be blinded by the "Rocky syndrome," having survived so long they refuse to give in. In the end, “nobody can make the decision except you,” says a former Al Gore manager. "And you have to make the decision in a way that you don't second guess yourself the rest of your life."