I wouldn't read too much into that. McCaskill is running unopposed on the Dem side. On the GOP side, we have a hotly contested three-way race.
There is one hotly contested Democrat race, in one congressional district: Russ Carnahan vs. Lacy Clay, two Dem congressmen fighting for one redistricted seat.
** Yep, was just viewing current results for 1st district:
L. Clay (i) 54.5% 10,596
R. Carnahan (i) 41.8% 8,129
C. Britton 3.7% 716
Jeeze...
Carnahans are like Kennedys and head lice.. very hard to get rid of.