Constitutional Efficacy of Federal Income Tax
The Constitution makes it quite clear that there shall be NO direct tax, and if there is it must be apportioned, aka the exact same for everyone, in spite of the IRS Jurisdictional statement. However, the Sixteenth Amendment gives Congress the ability to tax incomes of those they have jurisdiction over in the States, and ONLY that. This irrefutably gives Congress the power to directly tax
U.S. Citizens in the states, but this does not include Nationals as they are of separate jurisdictions, those being the states.
We know this because the jurisdictional statement makes it quite clear that the income tax only applies to U.S. Citizens and Residents. If the 16th amendment truly did give the Federal Government the ability to tax as broadly as it claims, this regulation would state something along the lines of “All those born or naturalized within the geographical area of the United States of America are imposed...”.
But it doesn’t, and while regulations are re-interpreted from U.S.C. and statutes at large, they still must be “arguably correct”.
https://constitution.congress.gov/constitution
Section 9, Paragraph 4
No Capitation, or other direct, Tax shall be laid, unless in Proportion to the Census or enumeration herein before directed to be taken.
Sixteenth Amendment
The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.
IRS Jurisdictional Statement on Income Tax
CFR 26 1.1-1 Section 1 of the Code imposes an income tax on the income of every individual who is a citizen or resident of the United States and, to the extent provided by section 871(b) or 877(b), on the income of a nonresident alien individual....

