Wow. Not surprising.
I, personally, had a problem, some years back, with a union I was a member of.
I was more or less "required" to join a union, several years ago, when I took on a new job. I really had no complaints because even after paying my union "dues" I was putting more money in the bank than I ever had done in my whole life. And the benefits were better than I could have ever imagined.
But, back in those days, although I was still pretty much a moderate/centrist/live-and-let-live kind of guy, I identified as a Republican. I voted pretty much along party lines and my yard signs were republican.
So, it always rubbed me the wrong way when I would see the union, using money the members (me) contributed to it, and donate it to democrat politicians. That really griped my ass.
And, to make matters worse, between job assignments, whilst "sitting on the bench" the union hall called me in to go to work doing campaign work for Russ Feingold, (full union scale pay, benefits, etc.,) I was not gathering votes or anything. I was just painting walls, fixing electrical fixtures, mostly building maintenance. I was not technically on Feingold's payroll. In fact, I don't even remember who's payroll I was on. I just know I got a paycheck, and my needed hours to maintain my benefits and membership were better served.
Anyways, all that never set well with me. Often, I was tempted to wear a pro-republican shirt to work just to "stick it to the man." But I knew better. I needed the hours.