Ummmmm I mentioned straight away that he's their elected Senator. 
As it stands It doesn't look like most of his constituents support this repeal. Still, that he's got time to go to a Koch Bros. event but keeps refusing to hold town halls, or severely limiting them and who can attend, says to me at least he's not willing to listen to them. 
And I at no time claimed that the Kochs were the only ones tossing out dosh in the system. I don't hold them to be a boogeyman as some on the left do. I just see them as part and parcel of a bigger problem. 
Still Gardner is doing quite a lot to avoid those who elected him and should be held to account for that along with other pols regardless of party.