Calling Mitt Romney a “mixed bag” when it comes to fiscal issues, Club For Growth President Chris Chocola offered a lukewarm appraisal of the Republican presidential nominee, saying he has the ability to exceed expectations if elected president, but that his future is opaque.

“We’ll see if he’ll be a pro-growth president. I think he has potential to exceed expectations,” Chocola, the head of the anti-tax group, said at a Christian Science Monitor breakfast in Washington.

What exactly are Chocola’s expectations for Romney?

“They are uncertain. That’s the thing. We don’t really know. That’s the knock against Romney, is you don’t really know how he’ll serve,” the former Indiana congressman added.

The club did not involve itself in the presidential primary, opting instead to focus on the congressional landscape, where it meddled in some high-profile Republican primaries including Indiana, where longtime Sen. Richard Lugar (R) was dislodged by Richard Mourdock, the club’s preferred candidate.