UNfortunately, most House seats have been districted in such a way as to make them safe for one party or the other- once you're in, you're in forever. They're not competitive. As much as the Republicans claim to value competition, that apparently doesn't apply to politics.
The redistricting in Colorado, my home state, was an effort to protect the first term republican incumbent in a rare competitive district. He only won by 200 votes or so, and hasn't proven to be particularly effective or popular. His pals want him to stay, however, so they tried to stack the deck in his favor.
With modern demographic mapping and computer modelling, redistricting can effectively deny the minority party anything more than token representation, which basically deprives voters of their right to choose. In a state with a near even registration split, much higher ratios of majority party candidates can be made winners, on the order of 80/20. As was said by insiders about the Texas redistricting, it can guarantee one party the majority despite the mood of the electorate.
That's not really my idea of Democracy. The notion that redistricting should occur whenever the majority party finds itself in the rare position to really screw over the other side isn't necessarily very smart, either. It can lead to partisan bloodbaths on a much shorter schedule than the usual 10 years, at needless expense to the taxpayers, in states controlled by either party... While that looks good to the Texas and Colorado Republicans, it might not work out so well in other states or in the future... Things change, and people do remember, particularly when you've done them dirty...