I agree that the sample doesn't make a difference in terms of who will win the state (it's SAFE Obama). But not sure I agree that Mitt's ceiling in MD is 37%. '08 was a banner year for Democrats w/ record-breaking turnout, and McCain still managed 36.5% of the vote there.
35% to 37% is basically a floor, McCain wasn't really going to dip below it, because the panhandle and Eastern Shore vote so heavily Republican. There's a short distance between the floor and ceiling for Romney, he won't drop below it, but he won't get much above it either.