Nobody on my side of the aisle is asking that question. The assumption is that he is guilty of collusion with Russia, among other things, and that he is more than impeachable. He is imprisonable.
There are a lot of reasons for believing in his guilt, beginning with the assumption that an innocent man does not behave the way that Donald Trump behaves. I agree with them, because Donald Trump is guilty of a great many things. There is never a reason to believe him innocent of anything. Read more about Is Donald Trump Innocent?