There are several types of 'conservatives'... and too many people in my opinion have gotten used to the Tom DeLay type.
If someone isn't a loudmouth outspoken jerk who will get 'in your face' then he must not be conservative enough.
In Mitt's case he is much more conservative on principle than many people give him credit for.
“In Mitt’s case he is much more conservative on principle than many people give him credit for.”
Perhaps the phrase I am looking for is “lacking in consistency.”