People like him and other hawks like Graham, McCain, Bush,... are the reason why I cannot fully identify with the Republican Party. If the GOP wants to reach out to younger voters, he will be the wrong candidate (I woukl support Paul).
While I get where you're coming from, the ACTUAL way to change that is to be a part of the conversation/join the party. The Democrats went from being a blatantly racist party to one that had a strong civil rights plank in the span of about 30 years in the mid-20th Century because people who were IN the party changed the discourse on the issue. It didn't happen by people who agreed with their other policies sitting on the sideline because they couldn't stomach being a Democrat yet.
Being a part of a party means nothing more than you're adding one more set of views to a group of people who are called "Republicans" or "Democrats." If you register as a Republican, there's one more non-hawk in the GOP than there was yesterday.