What about a theistic colleague who would fund a campaign against atheistic marriage? (More appropriate analogy would be someone who would fund the goal of establishing a national religion.) Will I refuse to work with such colleagues?

If the position is to be against someone-who-would-fund-blah as a CEO, but okay as a colleague, this doesn't seem to help depriving the campaign blah from being funded (as long as someone didn't plan to increase donation from increased remuneration as a CEO). If the position is to be against someone-who-would-fund-blah both as a CEO and a colleague, I am not sure I support that position.

The main point being, while setting company-wide policy is greatly helped by being CEO, funding campaigns is less so.