The cause should also be examined closely ~ and obviously the federal personal income tax has FAILED.
You apparently have an odd definition of “failed”. It has clearly not failed since it raises enormous revenues for the government year in and year out. How is it a failure of the tax scheme that the Congress spends money even faster than the tax brings in? It is precisely because it has NOT failed that so many object to it, particularly the inability to escape the taxing authorities.
Ideology and rhetoric aside there is no real alternative to an income tax if any significant military actions are contemplated. Military spending simply overwhelm any other form of taxation.
Given that this nation has become more of a democracy than a republic and that the poor/dissatisfied are always more numerous than the wealthy/satisfied the bias of the electorate is towards socialism. Add the emancipation of women into the equation and that bias becomes very difficult to counter. Our government has evolved from the Founders’ view as a result of what our People have wanted. While it may be realizing that it is NOT want it wanted any change will take decades.
There is a 35% sink of ignorance, apathy and evil which remains committed to this nation going on the wrong path. This is where the class warfare is most popular and effective. But it has been there in national politics since Jefferson declared war on the “banks”. It has been a force in every election since 1800.