Of course it's not surpsing that Kos, with his monstrous ego, believes that Tester's job is to represent him. Tester knows that his job is to represent the people of Montana. He's made clear that the opposition to DREAM in his state is overwhelming.
Kos took an active interest in moving Tester through the Democratic primary so in a sense it can be understood why he sees Tester’s votes as a betrayal. Roles reversed maybe we’d feel the same.
Best comparison would be Scott Brown. I know there are conservatives upset with him and speak of betrayal. My position has been what do you expect? An “R” in MASS is going to be Ronald Reagan? Come on. This is why I stick to conservative and swing or only slightly blue states to target. I ignore liberal bastions because I know what we can expect isn’t good.
That is my response to Kos. You elect a politician. Politicians want to keep their job...usually. The last two years of Democrats performing kamikaze missions was unusual.
It is not beyond the realm of possibility a Montana Democrat would fold on this. He should know that.