Why does the GOP eat their own?

I have been busy with work, so reading a bit less and not being so angry with the Political World.  However, I was struck this week by an article on John Boehner and the reaction of some Tea Party types to his leadership.  They called him a RINO.

Now if John Boehner is a Republican in Name Only, how are the GOP every going to win the Presidency again?  How are they going to achieve some influence over positive policy movements as opposed to simply blocking things by saying NO?

The GOP has real influence; they control the House and they have a blocking position in the Senate.  If they simply negotiated in good faith and dealt with the Democrats as realists, there would be a path to negotiation on things that would really bring the Budget onto a path in the right direction.

Just saying No is a disservice to the country and a path to no progress on a budget position that is unsustainable.  The AARP, after saying a balanced approach to Medicare and Social Security was needed in the fall, are now saying No to anything.  If the left and the right are just saying NO, we are not going to make any progress unless the people in the middle are talking to each other and crafting policies that represent both sides and take us in the right direction of a balancing the budget.

However, when the GOP center does something like that and gets called a RINO, they cannot negotiate and we do not make progress.  This is really a potential disaster somewhere down the road.