I’ve been meaning to discuss this for a while now, and Mirror of Justice beat me to it! The issue pertains to Thompson’s pro-abortion lobbying for the National Family Planning and Reproductive Health Association. His was hired to help “rescind a rule prohibiting abortion counseling at federally funded clinics”.
Let’s think about this. Formal cooperation in evil mean that a person “freely participates in the action(s) of a principal agent, or shares in the agent’s intention, either for its own sake or as a means to some other goal”. Needless to say, formal cooperation with an intrinsically evil act (such as abortion) is never morally licit. For Catholic politicians who support abortion, formal cooperation includes “consistently campaigning and voting for permissive” laws.
Let’s say a nameless Democratic politician supported rescinding the aforementioned rule in the legislature. Is there much difference between this person and Thompson on these moral grounds. Not really. And isn’t there something more than a little unseemly about not only supporting this position but trying to make money from it?
Of course, this does not mean a Catholic cannot vote for Thompson, or the nameless Democrat for that matter. See here for the full argument.