The Ron Paul campaign released an ad on Friday mocking other candidates for talking about the Etch A Sketch.

It is a rare example of Paul going after Romney, if only slightly. The main focus of the ad, which barely mentions Romney, is Rick Santorum and Newt Gingrich, who are both shown holding Etch A Sketches at campaign events. It then suggests that Ron Paul is focused on important issues, such as the economy and ending the wars.

The toy became a topic of conversation -- and an easy attack on Romney -- this week when spokesman Eric Fehrnstrom said that during the general election "everything changes, it's almost like an 'Etch A Sketch' ... You can kind of shake it up and restart all over again."

"This is an Etch A Sketch," Santorum says in a clip.

"An Etch A Sketch," Gingrich is shown saying next.

"We're talking about big things here first," Santorum says in a clip later, still holding the toy.

The ad "will be pushed to conservative email lists" and websites, according to a press release from the campaign.

In that statement, Paul Campaign Spokesman Jesse Benton said Fehrnstrom's comment was revealing of Romney's "flip-flops."

"Conservatives and Constitutionalists have long been concerned about Mitt Romney's track record of position changes and flip-flops, and his top adviser's slip of the tongue only reinforces this suspicion," Benton said. "It is equally off-putting to see Santorum and Gingrich react like carnival barkers, not the statesmen America sorely needs. But none of this is surprising,"