Palin should spend her time and PAC resources going after the 40-50 House RINOS in their home districts. Take them on in their own backyards. RINOS are enemy #1 and everyone knows it.
See my post earlier in this thread. It may be merely a semantic difference between us, but the enemy are CINOs, Conservative In Name Only. The Republican party has a heritage of eschewing Conservatism -- with the likes of George Norris, Thomas Dewey, Bob La Follette, Jacob Javits, Fiorello La Guardia, Olympia Collins, Bob Dole, Nelson Rockefeller and, sadly, far too many more fitting that profile.
The greatest president of my lifetime, Ronald Reagan, rose above the mere party label of "Republican" to lead a Conservative revolution, fighting the long-entrenched leadership of the party. In that sense, President Reagan was a rebellious RINO since he cast off the shackles of mere Republicanism to advance genuine Conservatism. He was the real deal.