It’s for face saving for Trump and his supporters. He can’t “lose.”
And it’s successful in distracting media attention from his loss.
I don’t believe Trump believes it; if he really has to, he needs help.
Indeed, after the huge Trumpertrantrum on twitter about how Cruz cheated, how Trump really won, how he abused poor Ben Carson, how the Iowa caucuses needed to be nullified and a new caucus held just for Donald Trump...the Donald Trump turned around on a dime, as though he had finally got around to taking his meds, and said “I don’t care about that anymore.”!!!
The dude is seriously unhinged.