The historical top rates were subject to a lot more deductions than we have today - effective tax rates were in the 40% range. Effective rates today are certainly lower, so your point stands, but the difference isn't as stark as just looking at marginal rates would presume.
I'd love to see examples of people who advocate raising tax rates glossing over marginal and effective rates. It would actually be to their advantage if more people understood the difference. The number of people who turn down raises because "My taxes will go up" is depressingly high (Any number > 0 is too damn high. You'd have to be deeply misinformed to turn down a raise because of taxes). Those are the same people likely to vote down higher tax rates on higher incomes.
On the other hand if you support lower tax rates, it's to your advantage for voters to be misinformed about this. The more people who think their taxes are going up, even though they aren't, the more people are likely to vote against raising the top tax brackets.
Ah, yes. That is true! What I had meant is that certain discussions can come up, such as, "that group needs to pay their fair share." Regardless of whether the group should pay more or not, the discussion is oftentimes not about tax rates as much as it is about simply paying more. In those sorts of discussions, what is actually currently being paid is rarely mentioned.
