First, he has money. He will raise substantially more than any would-be challenger. More money means a stronger organization, which is incredibly important for the front-loaded primary calendar. Jimmy Carter in 1976 could start slow and build momentum, but that is much more difficult now because of how early Super Tuesday is and how many primaries are on it. A candidate who lacks strong, positive name recognition and/or money to build state-by-state infrastructures will have an impossible time of competing.

Second, he has the White House. Ted Kennedy had an enormous lead over Jimmy Carter through all of 1979, but ultimately he carried just 35 percent of the primary vote in 1980. A big reason why was Carter’s excellent use of the Oval Office. Not only was Carter careful to dole out patronage in ways that helped him in the battle against Kennedy, but he also employed a masterful “Rose Garden Strategy,” in which he made a point every day to seem presidential. It worked like a charm.

Third, he has the Democratic client groups. While many liberals – like Harrop – are disappointed with Obama’s performance, the president has done an incredible job of appeasing the sundry client groups that make up the Democratic party.