The phrase Joe Biden uses when his opponent says something he has no logical counter to, in an attempt to discredit them without having to actually be able to form a cogent thought.
Hey Joe, there's actually a video tape of you admitting to blackmailing the Ukrainians.
O come on man, that has been totally debunked. my homies already said it didn't happen.
Blatently obvious. If a fat person tries to sneak round a corner they will be seen, as their belly will protrude first and give them away. Hence if something can be seen a mile off, or is really obvious, it can be 'seen coming like a fat man round the corner'