MO-Gravis: McCaskill leads narrowly

[Pollster]

Gravis' sampling method and voter screening is questionable - very strange that they are putting out polls of multiple states with candidates in the low-40's/high-30's despite virtually all other polls of the same races showing much less volatility.

Edit: Just saw that they sample registered voters only. This explains the larger amount of volatility, but their numbers are still overall strangely low.