GOP Radicalization: Can It Be Reversed?

Yes, under three conditions:

1.  Catastrophic electoral defeat:  Let’s say, hypothetically, Ted Cruz is the nominee in 2016, and he leads the party to a defeat comparable to 1964.  That might cause a reassessment of both tactics and policy.
2. A sweeping victory:  Now the realities of getting legislation through the system with widespread public opposition and the constitutional limits on federal power come to the fore.  The party will have to settle for less than the Reactionary agenda, and defend its failures.
3. The Reactionaries form a third party:  The remainder of the GOP is now free to cooperate with the Democrats on selected issues, and radical ideas are no longer in vogue.