This is true, yet often when it is brought up as you have done it is a straw man. The OP has in his mind that taxes collected are excessive. If you show him that rates are progressive, he won't decide that enough money is being collected after all. He is only using the tax rate as a rhetorical point -- he points elsewhere for proof that too much is collected.
Edit: should clarify I prepare taxes among other things. I'm NOT saying the brackets aren't progressive, just that this guy isn't saying, "gee, if only we progressed up to 35% things would be fine."
Most people in the middle and upper middle class complain that their taxes are too high in hopes that benevolent, democratically elected lawmakers will lower them. But it's a fact that Americans enjoy an effective tax rate that is quite low by both international and historical standards.
Of course, we're about to learn the consequences of that as we slowly decimate our educational system and national infrastructure, but that's probably a separate discussion.
Edit: should clarify I prepare taxes among other things. I'm NOT saying the brackets aren't progressive, just that this guy isn't saying, "gee, if only we progressed up to 35% things would be fine."