Just look at the house.
We do not have a majority of conservative reps there. However a core of dedicated conservatives have forced boner to be more conservative than he would be normally.
To pass a federal marriage amendment you don’t need the president. That would trump this fetish worship nonsense.
Your theory works okay when you have a democratic president. To some extent, the republicans work together against a common enemy. When the republican president decides he does not want a conservative idea to be passed, the core of dedicated people becomes the 300 fighting liberal Xerxes and his millions. A liberal republican gives RINOs cover.
It is already happening. Remember the House was going to de-fund Obamacare. Never happened. Funny how as soon as you get Romney as the frontrunner, all those plans go flying out the window and Boehner’s spine disappears unless it involves disciplining the conservatives.
With either one of these two running for president it will be difficult for all conservatives. We will need to get as many elected as we can and do all we can to hold their feet to the fire. The more conservatives we elect, the greater the chance even the RINOs in office will fear for their seats and even if things don’t go our way this time, next time those RINOs will be gone.