One should bear in mind the prime directive to government from the Tenth Article of the Bill of Rights:
“The powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people.”
As Thomas Jefferson wrote in the great declaration: “But when a long train of abuses and usurpation's, pursuing invariably the same object, evinces a design to reduce them under absolute despotism, it is their right, it is their duty, to throw off such government, and to provide new guards for their future security.”
As Patrick Henry argued at the Virginia convention which ultimately resulted in the ratification of the Bill of Rights: “Guard with jealous attention the public liberty. Suspect everyone who approaches that jewel. Unfortunately, nothing will preserve it but downright force. Whenever you give up that force, you are ruined.”
And clearly Article I, Section 8 gives Congress the power to call up the militia "to execute the Laws of the Union, suppress Insurrections and repel Invasions." So suppressing rebellion certainly isn't an abuse of the powers granted Congress.