Coerced removal of someone's rightfully earned wage.
“To compel a man to furnish funds for the propagation of ideas he disbelieves and abhors is sinful and tyrannical.”
-Thomas Jefferson
“A democracy cannot exist as a permanent form of government. It can only exist until the people discover they can vote themselves largess out of the public treasury. From that moment on, the majority always votes for the canidate promising the most benefits from the public treasury, with the result that democracy always collapses over a loose fiscal policy--to be followed by a dictatorship.”
-Alexander Fraser Tytler
"To take from one, because it is thought that his own industry and that of his fathers has acquired too much, in order to spare to others, who, or whose fathers have not exercised equal industry and skill, is to violate arbitrarily the first principle of association, —the guarantee to every one of a free exercise of his industry, & the fruits acquired by it.'"
-Thomas Jefferson.
Income tax specifically, is a form of legalized theft, depending on how it is used. And yes, that does matter.
For example, note the quotation at the top. Propagation of ideas he disbelieves. Does anyone disbelieve in law and order? Other than possibly the criminals themselves, no one disagrees with that. And everyone benefits from it equally. Thus it meets the "general welfare" clause.
So an income tax at the state and local level, is acceptable if everyone agrees to it, because everyone benefits from law and order.
But what about Welfare? Does everyone support welfare? No. Does everyone benefit from welfare equally? No. So coercing people to pay for it, is merely legalized theft.
The core functions of government, I would suggest to you, could easily be funded without the use of income tax, at least on the Federal level.