I'm not going to ignore my conscience just because doing the right thing would put another Republican in the White House.

That's crass partisan thinking, and it says more about you, as a Republican, than it does about me, that that's your first thought.

I don't know if Hastert would be a better President (though at this point the bar's pretty low). But although he's tainted by guilt-by-association in general as a Republican, he doesn't have the history with the public like Bush does. And he'd benefit from the coattails of Bush doing the right thing by resigning.

When Nixon resigned, Ford took over, another Republican. People were wary, but they gave him the benefit of the doubt. They didn't (re?)elect him first time he ran, but it seems, in memory, more a matter of just thanking him for being a good steward in the interim and retiring him with a gold watch for time served. He definitely didn't inherit the public's hatred of Nixon, and the 1976 election wasn't a repudiation of Ford, more just a natural desire for change.