CNN

Romney campaigned in New Hampshire Wednesday.

MANCHESTER, New Hampshire (CNN) - GOP White House hopeful Mitt Romney called former Tennessee Sen. Fred Thompson a "great potential" candidate Wednesday and said the "Law & Order" actor may bring a "Hollywood aura" to the Republican presidential field.

But Romney, the former governor of Massachusetts, brushed aside suggestions Thompson would emerge as the most conservative candidate in the race.

"We're not all equal conservatives," he said after a campaign event in Bedford, New Hampshire. "I'm not the most conservative on the stage by any means - I doubt he'll be the most conservative on every issue, either."

Thompson formed a committee last week to begin raising money for a potential White House bid. Aides to Thompson have said he could formally get into the race over the July 4 weekend.

Romney added that Thompson will be a "on TV a welcome feature to add to the mix" and said Thompson will likely increase the amount of viewers who watch the next GOP debate.

– CNN's Steve Brusk and Alexander Mooney