Now that Bush is gone, there is nothing and nobody else for the Republicans to turn to. They can either try to build a new identity for the party from scratch, or they can remain loyal to what they know, as so many 1930s-era Republicans remained loyal to the legacy left by Coolidge and Hoover. The latter course obviously doesn't offer much hope for the future (unless President Obama crashes and burns), but at least it promises safety for the present to the majority of Congressional Republicans representing safe Republican constituencies.
There's two things worth noting. First, those 30's era Republicans who remained loyal to Hoover and Coolidge in fact passed on their legacy -- to Barry Goldwater, Ron Reagan and ultimately George W Bush.
Secondly, there's a certain irony in the fact that Republicans took jerry-mandering to new heights, thinking it would enable them to hold onto their "permanent" majority. However, it seems to be having the effect of forcing Republicans to stick with a failed ideology, thereby ensuring their trivialization. Funny how that works.