Yes it's over. He has no path for victory.
Agreed here.
Sanders wasn't "done" on Super Tuesday. He's won a lot of states, and that gets people's attention, but he had to win NY to have a chance to (A) narrow the delegate gap, and (B) show the stuff to impress those superdelegates who are "party animals" that aren't totally in the tank for Hillary.
This didn't happen. The superdelegates, all of them, are leaning toward Hillary because Sanders isn't really a Democrat, isn't vested in the Democratic Party beyond the Democratic caucus in the Senate, and hasn't done much for other Democratic elected officials. Hillary is all about party, and that's appreciated; as guarded and phony as she is, she does care about whether other Democrats win because she knows she'll need cover and spear-carriers to succeed if she's elected. The superdelegates note Sanders's popularity in head-to-head polls, but they also are folks that are not likely to cozy up to a "Rage Against The Machine" candidate.