Despite a hard-charging speech over the weekend that suggested dissatisfaction with the Republican presidential primary frontrunner, Sarah Palin said Sunday that Mitt Romney “is a great candidate.”

But the 2008 vice presidential candidate and Tea Party darling isn’t yet convinced Romney is “instinctively” a constitutional conservative.

“I am not convinced and I don’t think that the majority of GOP and independent voters are convinced,” Palin told “Fox News Sunday.” “And that is why you don’t see Romney get over the hump. He’s still in the 30-percentile mark when it comes to approval and primary wins and caucus wins. He still hasn’t risen above that yet because we are not convinced.”