It suffered a pretty big body blow in 1996, and further in 1998, when after the 1994 elections, they actually tried to do conservative things in earnest - and got little popular support.
1. Kweisi Mfume began his bloody-shirt campaign at the NAACP to get black voters out in bigger numbers. He succeeded, and the black vote went up by as much as (if I got the arithmetic right) as much as 60% over what it had been in previous elections. That vote alone almost entirely accounted for the 1998 surprise.
2. In 1998, the Lewinsky scandal just about blotted out the sun and nearly paralyzed the Congress. It energized the 'Rats who, embittered as well as stunned, fell into lockstep behind Tom Daschle and gave us the memorable spectacle of their rah-rah rally for the Felon on the White House lawn on the day he was impeached.