See Article IV, Section 4. And then see the last clause of Section 8 of Article I.
See Article IV, Section 4. "The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic Violence."
And then see the last clause of Section 8 of Article I.
"The Congress shall have Power To...provide for the common Defence and general Welfare of the United States;"
OK, so right there, in the same clause, the Congress is supposed to provide for the defense of the country (Air Force) and the general welfare (Social Security). Would you argue that half the clause is invalid?