She probably said it because Mitt is our best realistic candidate from a conservative POV. She defined the 'realistic' set as Gingrich, Guliani, McCain, and Romney.
Her reasoning is sound. You can go for an electable non-conservative (Rudy) or a non-electable conservative (Duncan Hunter, Ron Paul, etc.). Mitt at the intersection of sufficient conservativeness and sufficient electability.
Wait a second, the REAL Conservatives (or so they call themselves) don't care about electablity ... principles mean everything. Even if your horse doesn't even cross the finish line.
I would have a hard time supporting Mr. Flip Flop.