Our tradition believes in “support that which we believe in and fight no one.” With this philosophy and the added caveat of knowing the perfection of all beings, my job is to speak to personal values and morals while honoring where that teaching may take you as an individual.
I think it is OK for a pastor to talk about politics to make a point in their sermon, if they can use the topic to help illustrate their point. If using Bill Clinton as an example to illustrate the consequences of lying about adultery will help get the point across, then it is fine.