Runoff Could Spell Trouble for Lincoln

The fact that Sen. Blanche Lincoln (D-Ark.) appears to be headed for a runoff doesn’t bode well for the incumbent’s re-election odds, according to history.

I consulted University of Georgia political scientist Charles Bullock, who co-wrote the definitive book on the subject, to confirm his study of runoff elections. Overall, whoever places first in a primary wins the runoff 71.8 percent of the time. (So far, looking good for Lincoln.) Things are even better for a Senate primary specifically — the Senate primary leader wins the runoff about 77 percent of the time. (Lt. Gov. Bill Halter beware.)

Not so fast. The odds of winning drop significantly when an incumbent is involved. If the incumbent is the leader in a primary race, he or she wins just 55 percent of the time. The premise behind this is if a voter is willing to vote against the incumbent once, the voter’s more likely to do it again in the runoff.

But that 55 percent applies to all primary races — and last night’s vote was a particularly close one. In an email, Bullock wrote that there are two factors important in the outcome of a runoff: the primary leader’s margin and whether the race is for statewide office. As of this morning, it appeared that Lincoln’s lead was two percentage points or less. The fact that it’s a statewide race means her prospects are even dimmer. So her chances are, by historical standards, likely considerably lower than 55 percent.

To sum it up, “things do not look good for Sen. Lincoln,” Bullock wrote in an email.