Article 1, Section 2 of the U.S. Constitution states: "... direct Taxes shall be apportioned among the several States ..." Article 1, Section 8 states: "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." Article XIV, Section 4 states: "The Validity of the public debt of the United States, authorized by law ... shall not be questioned."
We are told that all the Republicans in Congress have signed the Grover Norquist pledge that they will not vote to raise taxes. Such an extra-constitutional commitment creates an obvious conflict between the pledge and the constitutional duty. Is the Republican Party loyal to the Constitution or to Grover Norquist? As the Bible says, "You cannot serve two masters."
Since the Republicans are refusing to raise revenue to provide for the common defense and general welfare of the United States, they have chosen to serve Master Grover Norquist and to abandon their duty to the Constitution they have all sworn to uphold.