Turnover is at a historic low and getting worse. It's lower than in the Soviet Politburo, and most districts never have competitive elections. The last mid term was at least partially a reaction to that. However en-mass replacement is no better than perpetual incumbency, and blindly voting against everything is no better than being a rubber stamp. I think they're equally bad. To those that say it's worse - would it really have been bad if there had been congressional opposition to the Patriot Act and Iraq war from someone other than Bernie Sanders and Ron Paul?
To get better people, there needs to be rotation in office in a regularized fashion. Yes, that means Term Limits. I think limits on consecutive terms is a better than absolute limits. I.E. you can't run for the same seat in the election immediately following 2 consecutive terms, but can in the election immediately following. This solves the problem of incumbency without permanently barring good people. It's the system that was used in Greece and Rome, and was favored by many of the founding fathers.
It's even more helpful considering that currently, power in Congress and Senate is essentially based entirely on seniority.
Regarding Democracy vs. Law/Rights:
How do you suggest law and rights be strengthened? The staleness of congress is just leading to more and more use of executive power, more arbitrary and king-like rule.
If you want laws that are better and more followed, you need better people to write them, which is congress.