flop came down just garbage, and i check, he bets 1/2 my stack, and for the life of my, i do not know why i even thought about calling, BUT I RE-RAISED ALL-IN

At this point there is NO REASON for him to be bluffing as his bet creates a side pot if you want to create one. The reason this should never be a bluff is that he is betting half your stack, and he wins NOTHING if you fold, because of the all-in player.