Note that Jeff Sessions is from Alabama, of the era in which JFK enforced Brown against the governor George Wallace in 1963.
When the governor refused to step aside for the US Attorney accompanied by Federal Marshalls, JFK Federalized the Alabama National Guard to enforce the law. The General in charge ordered him to step aside.
And Wallace stepped aside.
I wonder if Trump could direct the FAA to close off flights to those cities airports. probably bad idea