The governor is the commander of the state's national guard. They can be nationalized through the governor. The guard is local people who have supported local politicians, many of them believing that Washington D.C. is out of control. If you have a flash point incident where the state government is under assault by the Federal govt. who are the leaders of that state's guard going to stand by, the governor and their state, or Washington D.C.?
We are not at the temperature where that flash could occur yet, but the stew is getting hotter by the day. Consider how much the temperature has gone up between the 2016 election and today.
Not sure if thats completely accurate or if you just need to clarify your wording. My understanding is that NG has two chains of command, but never both at the same time. They generally fall under the states governor, but if Federalized, they then fall under DoD.