"So let me speak directly to the delegates on this: If no candidate has a majority on the first ballot, I believe that you should only choose from a person who has actually participated in the primary. Count me out. I simply believe that if you want to be the nominee for our party – to be the president – you should actually run for it. I chose not to do this. Therefore, I should not be considered. Period. End of story."
Said Paul Ryan.
That's still one step short of a Sherman Statement. He didn't say If elected, I will not serve.