I play at PowerPlayer (same as PokerRoom pretty much), and I can't get hand histories for tournaments, but I'll try to reconstruct the situation the best I can. This is a 5 dollar MTT, about 700 people started, we're down to 90, top 60 pay. Table is ten handed.

I'm slightly above average at this point with 11K. Blinds are at 300/600. Here are all the important stack sizes I can remember.

EP (approx 20K)(has shown mild LAG tendencies)
MP (13K)(shown loose passive tendencies)
Hero (11K)
Button (3K)(no read)

EP player minraises to 1200. MP calls. I decide to call with my 88. My reasoning was that it was a relatively small portion of my stack, and losing the hand would really make little difference to my overall tournament position. I would still essentially be an average stack. If I got lucky and flopped a set though, I might be able to stack someone (or possibly multiple people), and become a big stack. In short, I like my implied odds.

So anyway, I make the call. Button then pushes behind me for 3000. EP and MP both call. I'm not 100% sure, but the fact that EP did not reraise the all in bet suggest to me that he does not have a higher pair. MP is a loose passive who could have a lot of things right here. I'm not sure about the short stack. Anyways, what should I do here? I obviously can't fold, as I'm getting better odds to flop a set now than I was before, however in the actual hand, there was so much money in the pot and I figured that EP and MP didn't have me dominated. Considering this, is the best play here to push, and try to maximize my chances of winning the pot (isolating against overcards, with a ton of dead money in the pot)?