I am a Trump supporter, but must admit it is NOT game over. Closed primaries are fish in a barrel for the GOPe, and Trump will do FAR less well in them. In the next chunk of states, 3/4 of the primaries are closed. The GOPe will use the combo of Rubio and Cruz attacks, coupled with perhaps $100 million in SuperPAC attacks ads on Trump, to hurt enthusiasm of his voters, drive down turnout, and help their people. This is likely going all the way to the convention.
Do not give up hope many many people changed their voting party in MA. They can still do this in Florida, and other states!!! We will see!!!