Which state in the U.S. or region has the most Polish-American vote bloc and which party can win them over in the future or does it make a difference?
The Midwest and urban areas in the Northeast have a lot of Polish Americans. Illinois especially has a large number, even having some state agencies that give somebody an option to press "3 for Polski" on their hotlines. Politically speaking, the Poles seem to have a voting habit very similar to the Irish, with a few exceptions (Hoover in '28, Ike in '52). In short, they look like a traditionally Democratic group that will vote Republican for the right candidate.
http://en.wikipedia.org/wiki/Polish-American_vote#Presidential_voting_results