The day he takes over in the superdel commitment race, not the pledged del race. He's been ahead in the pledged del race since Iowa. Man alive, at this point you'd think you could get the terms straight.
"Pledged" = earned in primary or caucus.
"Super" = can do whatever the hell they want, even after commiting, but we count them up based on what they say they'll do a la House whips anyway.