Plenty of Republicans don't consider Trump "one of their own".
Those are old quotes, PIA. He owns them all now, lock stock and pork barrel. The Republican Party is little more than a subsidiary of the Trump Organization.
87% of Republicans approve of the job Trump is doing. Mueller is a Republican and is likely in that number. He could have brought Trump down. Either he chose not to or Trump is innocent. You're gonna have a hard time convincing me that Trump is innocent.