I would say learn to separate opinion from facts pertinent to your class...Don't question people's opinion, just know that it's just that.

If it's not related to what he's teaching, then let it go.

If it is, then he should welcome a healthy discussion of it and he'll most likely favor you for it (my husband teaches and his biggest issue is that students don't think for themselves, they just want the facts that they can regurgitate on a test....)