If you believe this, you are a d@mn fool. This may indeed be the case for the first few years. But soon enough, that top 30% will figure out how to hide their assets better and taxes will have to go up yet again on the bottom 70%.
Any educated married couple who work will by the end of their working careers rise into the top 30%. A lot of this "class" division is artificial, the jealousy of a 20 year old for the earnings of a 40 year old when by the time he is 40 will have the same salary expectations.