From an article that already shows conservatives skirting self-parody by arguing that the poor need to pay more taxes:

William W. Beach, an economist at the Heritage Foundation think tank, said he was sympathetic to Lindsey's argument that the Social Security tax is not really a tax. But, he said, it was a dangerous argument for a Republican to make.

"Do I allow defense spending to offset my income taxes since I like to be defended? Do I allow road taxes to offset my profits taxes because I use the roads?" he asked. "If you do start down that road, it's hard to see anything as taxes."

Sure, if by "taxes" you mean "money that gets thrown into a government incinerator somewhere", as many devout anti-tax advocates undoubtedly believe. If taxes are actually, y'know, used to pay for something, well that's entirely different isn't it?

(Well, let's be fair. The question is whether it might actually be used to benefit somebody else, instead of the taxpayer in question. Because there's no such thing as citizenship and whatnot.)