One of the main tools Governor Abbott has used to secure the Texas border is the National Guard. Now Biden wants to take that resource away from the people of Texas. Biden has announced plans to fold the Texas Air National Guard into the United States Space Force.
Normally, a president needs a good reason to federalize the National Guard, so this creates a gray area. Military Attorney Sean Timmons says, "The President as commander in chief has control of the military forces. But the Texas Guard is separate and distinct, and the Governor is the commander in chief of the guard, so it's a real muck."
Timmons says this is clearly retaliation from Biden for Greg Abbott's efforts to stop the Biden Border Crisis. He also said that this is a clear interference with the state's need to defend itself. This is an issue that will likely end up in the courts and could go all the way to the Supreme Court before it's settled.