Maybe not Mark Foley alone.
But add into the mix:
disgrace Congressmen Fey, and Cunningham, (two GOPers now heading off to jail),
that idiotic preacher from Colorado (who claimed to practice conservatism),
the failure of the GOP congress to curb illegal immigration,
the bigtime overspending,
the failure of Pres. Bush to articulate some type of winning strategy in Iraq (other than "we must win"),
and yes, even the hurtful and boneheaded thing Rush Limbaugh said about Michael J. Fox's Parkinsons disease
and you have a demoralized Republican base.
Not, not everyone was demoralized.
But when 5-percent of your voter base is demoralized, you will lose all those razor thin elections you've won the past 12 years.
-- and That's what happened.
I agree with your assessment but I would add one thing. Border fence.