Paul is the Libertarian. For the most part, Romney is the Financial Conservative.
Tonight, as Perry got bogged down with in tonight's debate facing his unpopular decision to mandate a teen vaccination in Texas, and his loose stance on illegal immigration, Michele Bachmann, began to take his place with the Tea Party as the hard right conservative. Not only is Perry's use of executive order scary, but as Santorum pointed out, so is his view of the role of Government(mandating a vaccination).
To Tea Party supporters, Perry began to show that he's not quite as 'airtight' of a conservative as many would have hoped.