a) Contributing financially to many religious institutions is explicitly financing groups who opposed gay marriage, and is an activity than many religious people undertake.
b) Advocating for something that in some views is unconstitutional is a constitutionally protected activity. The practice itself may be unconstitutional (I certainly think so), however, the political advocacy itself is not.
b) Advocating for something that is purely prejudicial and hateful is deserving of censure.
As I said, I'm not entirely sure how I feel about holding people accountable for their political views in general, but I do have some rationale for leaning toward censure in this particular case.
I don't even agree with these people, but people who express views like yours - that we should censor views we find distasteful so they can't even be discussed openly - make it really hard to comfortably take a stand against them.
I'm not for censorship, even of views I find extremely distasteful, and don't advocating punishing people merely for holding or articulating them.
Is there any evidence he's done anything besides be part of the political process, such as discriminate in the running of the nonprofit?
*Edit to fix typo.