I don't think they are embarrassed because most of them belong to the same pot. They appeal to their base. I don't think most of the senators who claim that climate change is not real, really believe it. They just say it to appeal to their "fossil fuel buddies."
If you see them speak otherwise, they seem to be quite intelligent, certainly intelligent enough to see that the weather patterns are changing drastically all over the world. "It is easy to wake a sleeping man, but it is impossible to wake a man pretending to be asleep."