How to mitigate "bandwagon attacking" from players?
Use this bias in your favor!
Some players just won't listen to the most reasonable arguments.  Trying to convince them that you were attacked enough won't work, instead use their biases in our own favor.  Don't lead on the start of the game, try to be the second strongest player, then stay quiet while others attack the leader.  It is nice to see everybody team up to destroy the leader, giving you an easy win.

In those kind of games, being second is usually the best in terms of winning probability. 

I will add to the reference list:


Catan
Struggle of Empires
Munchkin


Of course this "stalling" strategy is groupthink dependent, looks like that in your gaming group it will work like a charm.