Rick Santorum's campaign has started running a television ad in Michigan that attacks Mitt Romney for going negative in the GOP race for the White House.  The ad features a Romney look-alike shooting mud pellets at a cardboard cutout of Santorum.

It's called "Rombo."

The Santorum ad comes a day after the Super PAC "Restore Our Future" started running an attack ad against Santorum.

Several polls in recent days have shown Santorum in the lead in Michigan, which votes on February 28 along with Arizona.

Which ad will work better?  Let me know what you think.