I ask, out of charity and in an act of fraternal correction, that every Catholic who voted for Barack Obama to go confess their sins and refrain from Holy Communion before they do so. Clearly, they delivered him the election in several states.
The Masked Chicken, over at WDTPRS.com, has a good explanation in the combox of then-Cardinal Ratzinger's explanation of voting for pro-abortion candidates HERE. Look, Romney wasn't perfect, but he was our best option, and we need to work to get away from both parties, who both cause evil, and it's harmful to be in a marriage of convenience to the GOP.
There's a lot to be said about conscience. I for one am not convinced that anyone can vote for Obama in good conscience, all things considered (knowledge of candidates, knowledge of Church teaching, and reasons for supporting candidate).