The President does, in fact, have the authority to call up the National Guard and other state militia per 10 U.S. Code § 252 - Use of militia and armed forces to enforce Federal authority and 10 U.S. Code § 253 - Interference with State and Federal law. The governor of the pertinent state ostensibly still has control over these forces; however per 10 U.S. Code § 254 - Proclamation to disperse:
Whenever the President considers it necessary to use the militia or the armed forces under this chapter, he shall, by proclamation, immediately order the insurgents to disperse and retire peaceably to their abodes within a limited time.
This would seem to imply that these forces could be used to enforce this proclamation.