[Jim W N]

The power of Article IV Section 4 is it is a FEDERAL MANDATE (”SHALL”).

Article I Section 8 is more of a provision at the discretion of Congress (rots a ruck).

Article I Section 10 is a good one at the state level - states’ right to take action unilaterally if necessary.

[Political Junkie Too]

Yes, Article I Section 8 requires Congress to act, ideally at the insistence of the President, but they can act alone.

However, the called up militia will report to the President, so the check and balance is that the President doesn't have to deploy them (e.g., Obama would let them rot if a Republican Congress called them up, and a Republican Congress won't call them up because they know that Trump would deploy them).