Key provisions in the Constitution relating to taxation are summarized below:

Representatives and direct Taxes shall be apportioned among the several States, which may be included within the Union, according to their respective Numbers, which shall be determined... [every 10 years by census]. 

Section 7 [Paragraph 1] 

All Bills for raising Revenue shall originate in the House of Representatives; but the Senate may propose or concur with Amendments as on other Bills. 

 

Section 8 [Paragraph 1] 

The Congress shall have Power To lay and collect Taxes, Duties, imposts and Excises, to pay the debts and provide for the common Defense and General Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States.

The Migration or Importation of Such Persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the Year one thousand eight hundred and eight, but a Tax or duty may be imposed on such importation, not exceeding ten dollars for each Person. 

[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. 

[Paragraph 5] 

No Tax or Duty shall be laid on Articles exported from any State. 

Section 10 [Paragraph 2] 

No State shall, without the consent of the Congress, lay any Imposts or Duties on Imports or Exports, except what may be absolutely necessary for executing its inspection Laws; and the net Produce of all Duties and Imposts, laid by any State on Imports or Exports, shall be for the Use of the Treasury of the United States; and all such Laws shall be subject to the Revision and Controul of the Congress. 

Amendment XVI Section 1 

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. 

Amendment XXIV Section 1 

The right of citizens of the United States to vote in any primary or other election for President or Vice President, for electors for President or Vice President, or for Senator or Representative in Congress, shall not be denied or abridged by the United States, or any State by reason of failure to pay any poll or other tax.