I've read several predictions for the House elections in 2010 and they seem to ignore the fact that the Republicans are making asses of themselves and alienating the woman/black/hispanic/miscellaneous vote.
First, if Sotomayor turns out to be a racist or have radical views on affirmative action and such (not saying she does) this will only hurt Obama's, and by extension, the Democrats' credibility with
all voters, including Hispanics. Women will have leaned Democrat for quite some time, and not just because of abortion. Blacks are the same way.
I really think Republicans will make inroads with Hispanics, particularly because they've toned down the anti-immigrant rhetoric significantly.