I've, just (an hour ago) sent the link to this article to my Progressive (his term) brother.

If these clergy endorse a particular candidate or ballot measure, as such, from their pulpit, I believe I believe their tax exempt status should be removed. This should apply to any part of the religious continuum.

In nearby Pasadena, a liberal Minister come very close to do doing this very thing during the primaries of the past eighteen months. While the IRS took a long, hard look, nothing happened to him or the church.

BTW, I do believe clergy have the right and duty to sermonize on the religious, moral and ethical facets of issues, but should stop short of actual endorsement or telling congregants how to vote