Once he decides, it could be a big deal for the outcome of the caucuses, given his popularity in the state: Harkin yet to make endorsement choice.

My guess is that he’ll endorse Dean, especially given the Gore and Bradley endorsements, and the Des Moines Register reports:

Sources close to Harkin said last week he had been weighing an endorsement of Dean, the former governor of Vermont, whom Harkin has credited with energizing Democrats and running an aggressive campaign.

There is also the cynical possibility that Harkin will decide based on how he interprets the polling. Better to endorse the presumptive winner and appear to be a king-maker than to endorse a loser and look impotent in one’s own state.