I don't think Bush lost them for the party.
McCollum was weak(bad on 2nd amendment, and terrible on the 4th amendment.) Spence Abraham beat himself with his immigration stance, trade positions, weak campaign, bad front office and wishy washyness. Ashcroft was victim of bad luck with the plane crash. Slade Gorton was probably an age and $$$ victim. Bill Roth's trouble was age and that he was facing a governor.
The public's increasing bias towards divided governmentTheir increasing bias towards divided government, which they demonstrated by voting Republicans control of the Senate, the House, then the Senate again after Jumpin' Jeffords threw it over to the Democrats, the Presidency, and the majority of governorships to the Republicans while also increasing their representation in state legislatures.
I sure hope they continue to demonstrate their love of divided government just as well as they have since 2000!
There is no doubt that Democrats did well in Senate races in 2000.