If the GOP pushes the ILLEGAL ALIEN amnesty bill through they are finished and will go the way of the Whig party.
The 70 republicans planning a revolt need to break off from the party and create a new third party. This is the only way a new party can be started, they have to lead from within Congress. It cannot be started from the outside via grassroots, TEA party, etc etc. There are several parties all created on the outside who have never been able to make a dent in Congress.
If you want to change the dynamics and power structure of Congress to be a true threat to the establishment Representatives like Gohmert, Gowdy, Steve King and Senators like Cruz, Lee, Paul will have to come together and create a new party. Otherwise take a look at California and Detroit, that is your future America!