Only if you're voting against someone. The Democrats tried this in 2004 with their "Anyone But Bush" campaign, and it failed. Now, I see a lot of Republicans (primarily supporters of Guiliani) with a "Anyone But Hillary" mantra.
As for your prediction, it falls flat. You discount the media's ability to paint the attacking Republican as "mean", "racist, or "sexist"; or their ability to flat-out ignore the story (as they will likely do with this ad). It's a stacked deck.
They almost won in 2004, even with a loser like Kerry running...I believe if we stop bickering, pull together and agree to vote for whomever we want to in the primary, but support the winner for the national election so that Hillary Clinton doesn’t have any controlling authority over General Petraeus and our fine troops. Her comments this week ought to be a slap in the face for anyone NOT voting (R) in the general election. If people want to be a “one issue” voter, then atleast let that one issue be for our national security which we won’t have under a demoncRAT!
Don't get me wrong, Fidel is a commie pig, but there is a time and place---AFTER you win the election.
Republicans want a fighter. Any Republican who is busy attacking other Republicans won't have a hope in hell of winning a general election.