Kevin Williamson writes at National Review:
I have for a long time been sympathetic to the idea of capping the total annual taxes paid by an individual, say at $1 million a year. I call it the Max Tax. ... Barack Obama used to say that, at a certain point, you've made enough money. I think that, at a certain point, you've paid enough tax, at least for the year. The Left likes to talk about "fair share," even though right now, as things stand, the top 20 percent of income earners pay basically all the federal income tax — their share of taxes is wildly disproportionate to their share of income. Call me old-fashioned, but I think a million bucks a year is more than one's "fair share." I like the idea of other tax caps, too: For example, I'd cap the lifetime property taxes on a residence at the price of the house itself. If you've paid off your house once, and then paid for it again through property taxes, it should be, at long last, your house. ...
If you pay a million bucks in taxes, you shouldn't get a visit from a guy with his hand out asking for more. You should probably get a thank-you card. I don't care if you made $1 billion this year — I don't care if you made $1 billion this week — a million bucks is a lot of money.
The Social Security part of the payroll tax already works that way — the tax stops once you reach a cap. The political pressure seems mostly in the direction of lifting the cap on the payroll tax rather than extending the cap idea to other parts of the tax code.