Close Contests in Four Key States

Nearly six in ten voters in each of the four states said that the vice presidential picks "have little to do with" their presidential vote. That number was highest in Wisconsin (65 percent) and lowest in Colorado (58 percent).

Despite the lack of influence on voting patterns, both Palin and Delaware Sen. Joe Biden were widely regarded as strong picks by voters in all four states. Palin's high water mark was in Wisconsin where 57 percent said she was a "good choice" while just 33 percent said she had been a "bad choice." In both Colorado and Minnesota, 52 percent of those tested said Biden had been a "good choice" as vice president.

And, McCain's attempt to shift his message from one of experience to one of change does not appear to be resonating in the battleground states yet. In each the four states polled nearly twice as many voters said that Obama is the "candidate who will bring change" as say the same of McCain.

McCain does, however, enter the first presidential debate -- centered on foreign policy matters -- with a clear edge over Obama. More than six in ten voters in each of the four states said McCain "better understands" foreign policy matters -- including more than three in ten self-identified Democrats. The debate will take place Friday at the University of Mississippi at 9 p.m. ET.

The four polls were in the field from Sept. 14-21. The sample of likely voters varied by state: Michigan 1,364, Minnesota 1,301, Wisconsin 1,313, Colorado 1,418.