I can understand not wanting to claim him. He was what he was and that was what he claimed to be. Such is life.
Read Mein Kampf if you want further insight. Too bad more people didn't when it mattered.
Hitler rose to power, not on the Catholic Democratic ticket but with the Nationalist-Socialist party. Nationalism and Socialism are both Secular creeds and That is what he claimed. I can understand if you want to disassociate yourself from him, though.