Since when do conservatives support liberals like Romney and remain conservative?
A lot of conservatives who did not like Romney preferred him over the Commie-in Chief. Even JR came around and basically endorsed Romney.
When it's a choice between Romney and Obama, people would consider Romney as the lesser of two evils.
Others would reject that, prefer the greater evil get elected, under the assumption that this would lead to a resurgence of Conservatism, whose emergence would lead to more than making up for having four more years of Obama.
It remains to be seen whether any resurgence will save the Constitution in time. If Amnesty passes, we're done.