Think about it. Bush vetos a bill that was well received not just by Dems but by Republicans as well.
Why?
Becasue it gives Repubs who are not it whacko deep-red states the chance to DISTANCE themselves from this lamest of lame ducks, thus increasing their chances of re-election.
So Bush/Rove, throws them a bone, "here, run against me on this", to help them get re-elected and stave off a Democratic majority that would impeach his ass!
Veto=criticism from moderate Repubs/voters=reelected Moderate Repubs=two more years of this LOSER.
Makes sense, no?