McCaskill's biggest asset -- her personal favorability -- isn't as big as she may have hoped. Just 37 percent of Missouri voters have a favorable impression of the first-term Democrat, while 44 percent see her unfavorably. All three Republicans have lower favorable ratings as they build their name recognition, giving McCaskill the opportunity to boost their negatives. And she's trying -- McCaskill has debuted negative ads against all three candidates (Though her ad against Akin looks more like a positive spot aimed at boosting him in the Republican primary). Not all is lost for Missouri Democrats, though: The poll shows Gov. Jay Nixon is in position to win a second term this fall. Nixon would take 48 percent of the vote against businessman Dave Spence, the poll shows. Nixon holds a huge 52 percent to 31 percent margin among independent voters. Spence has a big advantage in the Republican primary, the poll shows. Take a look at the full poll results here, on the Post-Dispatch's website.