Can some Obama supporter explain to me the rationale for declaring victory on May 20 instead of when he gets 2,025 delegates? He has to know that the May 20 declaration will be disputed, and that it will cause acrimony between his and Hillary's campaign, and it will make him look as if he is trying to railroad himself through the nomination, all for what, a measly 3 weeks?
The only explanation I can think of is that they feel less secure than they want everyone to think over there in camp Obama.
I would imagine:
Not declaring victory on that date might appear as a concession that they don't genuinely believe that is the "true clinch" date. "We'll wait and see" would be tipping their hand to the Clinton people, and they're afraid of giving a mile by giving an inch.