Militia

The Militia:

There's nothing wrong with state lawmakers organizing a militia. As long as you don't....

...some conservative members of the Oklahoma Legislature say they would like to create a new volunteer militia to help defend against what they believe are improper federal infringements on state sovereignty.... the proponents say they don't know how an armed force would be organized nor how a state-based militia could block federal mandates.

Well, it can't.

Article I of the US Constitution holds that Congress has the power:

To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;

To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress.

Article II states:

The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States; he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any subject relating to the Duties of their respective Offices, and he shall have Power to Grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment.

So, the state has a perfect right to form a militia. However, Congress has the power to call that militia into Federal service, which places them under the direct command of the President of the United States.

You simply cannot Constitutionally create a state militia for the purpose of resisting the Federal government. The Constitution clearly establishes the authority of the Federal government to command any such militias, explicitly in the case of insurrection.