Besides, World War II could never have been paid for without an income tax.
In case you didn't know, the income tax was not implemented to pay for any war, historically it didn't serve to accomplish that for the civil war, they had to inflate the money supply and pay bonds off with devalued currency after they found the income tax to be insufficient at that time.
No there is only one reason to have an income tax and that was clearly described in a 1946 policy paper by FDR's advisor on taxation.
The Individual income tax is for political and social control not revenue collection.
"TAXES FOR REVENUE ARE OBSOLETE
-by Beardsley Ruml, Chairman of the Federal Reserve Bank of New York & advisor to FDR on taxation.
January 1946 issue of "American Affairs"
And in the Manifesto of the Communist Party, by Karl Marx and Frederick Engels, published in 1848. Among their recommendations are these:
The proletariat will use its political supremacy to wrest, by degree, all capital from the bourgeoisie, to centralize all instruments of production in the hands of the state ... . Of course, in the beginning, this cannot be effected except by means of despotic inroads on the rights of property ... . These measures will, of course, be different in different countries. Nevertheless, in most advanced countries, the following will be pretty generally applicable.
1. Abolition of property in land and application of all rents of land to public purposes.
2. A heavy progressive or graduated income tax.
3. Abolition of all rights of inheritance.
4. Confiscation of the property of all emigrants and rebels.
5. Centralization of credit in the banks of the state, by means of a national bank with state capital and an exclusive monopoly.
6. Centralization of the means of communication and transport in he hands of the state.
7. Extension of factories and instruments of production owned by the state; the bringing into cultivation of waste lands, and the improvement of the soil generally in accordance with a common plan.
8. Equal obligation of all to work. Establishment of industrial armies, especially for agriculture.
9. Combination of agriculture with manufacturing industries; gradual abolition of all the distinction between town and country by a more equable distribution of the populace over the country.
10. Free education for all children in public schools. Abolition of children's factory labor in its present form. Combination of education with industrial production, etc.
That is a situation that must end with the repeal of the income tax from the statutes, and the prohibition of its use by Constitutional amendment that future generations will not face the same manner of manipulation and interference in their lives.