Several members of Congress, the noisiest being Senator Rand Paul have stated the President acting as he did, was unconstitutional. He is factually wrong. Read the following:
the War Powers Act. BrE. a US law passed in 1973 which allows Congress to
limit the President's use of military forces. It states that the
President must tell Congress within 48 hours if he sends armed forces
anywhere, and Congress must give approval for them to stay there for
more than 90 days.
This means Trump could have invaded if he chose, unless congress disapproved, for up to 90 days. How about toning down the negative rhetoric and just sticking to the facts.
None of the usual cable and/or broadcast news sources have brought this up.