They do, and even more so than what they should be, willing or unwilling (more common). They pay for the lower class's and some of the middle lower class's taxes. Some even overpay. During Rachel Maddow's flop on getting Trump on his taxes, it was revealed he was actually paying a much higher percentage than what he should be paying (I can't remember what it was, but it was in the ball park around of between 35-40%, maybe more). If you want fairness for our tax system, I'm not opposed to a flat tax rate. I like Ted Cruz's idea for making it a flat 10%, then there's no question. So if you're worried about a millionaire paying a lesser tax rate than a doctor, there you go. I'm gonna throw out numbers, but if the doctor makes $100,000 a year, with a the flat tax rate of 10% he would pay $10,000. For a millionaire making $1,000,000, he would pay $100,000. To me, that's fair.
I'd go a step further, though, and eliminate the federal income tax. I don't think it's fair at all to punish anyone's financial success (big or small). That should be a state affair when it comes to those kinds of taxes, not a federal one. Even then, an income tax only causes damage to someone's pocket, not fix. Besides, it goes into the pocket of government officials like Crazy Bernie. Taking him as an example, it was also revealed that Crazy Bernie only paid around a 12% tax rate, and he's a millionaire. Of course, you want to talk about corporate tax cheats, Mark Zuckerburg denounces his citizenship around tax time, every year, and moves out of the country until tax season is done, then flies back. If I'm not mistaken, the federal government is already on his case about that, and he owes much in taxes for Facebook (this would be one of the only times where the feds get involved). To this day, I don't think he's paid yet. Both Crazy Bernie and Zuckerburg are the type of people that really do need to get in line with everyone else. So yes, those are the people that need to pay as much as the doctor. Not much worse out there than tax cheats like them when it comes to taxes.