The entire Democratic party gave up their support of the working class back in the '80s and joined the RNC in its goal of covering for the wealthy and their corporate cash cows. The difference between them is that the DNC can command a higher level of bribery because they are assumed to be still the working man's champion, so they don't have as much to lose by "not" providing that cover. The RNC is simply following its stated methodology when it cuts taxes on top earners. They don't get as much credit when they do what they say they will do.