[tagtastic]

You're up against another set, a straight, a big draw (A2c-A5c) or a horribly played overpair (this line is not that uncommon for JJ-AA on Party I'm happy to say).

You're beating 3 out of these 4 situations pretty badly (he's 30% at best) and if he has the straight, you're still 35% to win (30% if he has the best possible here, 4c5c).

The 3 out of 4 things you're beating can definitely outdraw you, therefore pushing is your only move. I wouldn't be surprised to see 45s more likely than any other hand here, however I still think this push is definitely +EV.