Bernstein sketches it out:

if party leaders don't want Palin to be nominated, her chances are slim at best.  My assumption is that most Republican leaders should be capable of seeing that Palin would be a poor general election candidate and a potentially disastrous president for them if she was elected.  If they can't see that, and support her despite all the warning signs, it seems to me that it will constitute fairly strong evidence that Republican pols and the people they listen to have entered the closed information loop that Sanchez discusses.