A labor question for Betty Sutton

I just submitted the following question to my Representative, Betty Sutton (D-OH):

Should unions be allowed to make financial contributions to a politician or organization using funds from a union member's dues if he/she objects? Why or why not? For the purposes of this hypothetical, assume that no court has ruled on the issue.

We'll see how (or if) this labor lawyer responds. I suspect she'll send a canned reply with no specifics.