Well that goes both ways. In CA its gerrymandered for the Dems. Also, both sides help each other because incumbents want to be reelected before they care about the good of their constituents.The Repub's getting all the Governors and legislative seats in local election is really depressing... god I hate gerrymandering.
In CA we have a proposition on the ballot (20) that will put redistricting in the hands of a 15 member citizen's committee. We already passed this for redistricting state seat in 2008. This is to do so for national (House of Rep) seats as well.
The politicians have a rival proposition (27) to restore their ability to redistrict.