The correct answer to this is:
Originally Posted by TRB1965
The real question is whether or not the 150 raise by small blind has "reopened" the pot. Since the raise was less than the minimum raise, I believe it has not reopened the pot.
Now if the BB were to raise the pot (perhaps attempting to isolate the all in), then the dealer would certainly be able to re-raise.
Originally Posted by OzExorcist
TDA Rule 10 (http://www.pokertda.com/rules.pdf):
In this case, a full raise is 200 and the small blind has shoved for only 150 more. So the button can either fold or call, but he can't raise.
Any other commentary about it being handled differently for NL (where something less than a full raise reopens the pot) is an exception by a house/organizer that doesn't actually know the correct rule or had to make a ruling for some reason. I've seen it argued by many people before, but the 50% rule only applies to Limit poker. So unless there is some valid reason or ruling as to why something less that a full raise would reopen the pot, there is no reason to perpetuate that exception especially in a home game where people constantly play by the wrong rules for no reason.
Additionally, from the NL/PL section of Robert's Rules of Poker (which fully supports the TDA rule):
3. All raises must be equal to or greater than the size of the previous bet or raise on that betting round, except for an all-in wager. Example: Player A bets 100 and player B raises to 200. Player C wishing to raise must raise at least 100 more, making the total bet at least 300. A player who has already acted and is not facing a fullsize wager may not subsequently raise an all-in bet that is less than the minimum bet or less than the full size of the last bet or raise. (The half-the-size rule for reopening the betting is for limit poker only.)