As usual, David Frum...

...is spot-on (my emphasis):

The identification of the GOP as mouthpiece for the selfish interests of the wealthy is a stubborn image, difficult to overcome at the best of times. For three years, however, Republican leaders have been doing their utmost to confirm the stereotype – and to quash and quell any attempt to counter that stereotype. Did we really spend months and months arguing that one of the things most wrong with the US tax code is that the poor and unemployed pay too little tax? Yes we did. Head shake. Face slap.