That's how guilt-by-association works. Make a charge and then -- once your attack is out there -- pretend that your words have been misinterpreted. Split your opponents. Put them on the defensive. Force them to say things like: "No, we're not soft on terrorism," or, "I'm not that kind of liberal." Once this happens, the attacker has already won.
Respectable opinion treats Rove's speech as just another partisan flap. It's much more. It's the reincarnation of a style of politics that turns political opponents into traitors or dupes who are soft on the nation's enemies. Welcome back to the '50s.