A new Mason-Dixon poll in Arkansas shows Sen. Blanche Lincoln (D-AR) with a 12-point lead over challenger Bill Halter (D) for the Democratic Senate nomination, 44% to 32%. Another 7% chose D.C. Morrison and 17% were undecided.
A January poll had Lincoln ahead by 18 points, 52% to 34%.
Pollster Brad Coker notes that with Morrison now in the mix and Lincoln's numbers sliding, a Democratic primary runoff appears "very plausible."
However, both Democrats trail likely GOP nominee John Boozman (R) by significant margins.