I hope this means he is going to be more vocal; an excerpt:

When I joined the military, some 50 years ago, I swore an oath to support and defend the Constitution. Never did I dream that troops taking that same oath would be ordered under any circumstance to violate the Constitutional rights of their fellow citizens—much less to provide a bizarre photo op for the elected commander-in-chief, with military leadership standing alongside….

 Donald Trump is the first president in my lifetime who does not try to unite the American people—does not even pretend to try. Instead he tries to divide us. We are witnessing the consequences of three years of this deliberate effort. We are witnessing the consequences of three years without mature leadership. We can unite without him, drawing on the strengths inherent in our civil society. This will not be easy, as the past few days have shown, but we owe it to our fellow citizens; to past generations that bled to defend our promise; and to our children.

ADDENDUM (June 6):  I've removed my little joke about a military coup in favor of VP Pence.   I have, it appears, more faith in the U.S. military, and its commitment to the rule of law, than most readers.

UPDATE (June 6):  This new Lincoln Project ad will surely drive Trump crazy: