I'm going to assume that you are a young person and have never experienced anything other than today's polarized politics which started with Newt Gingrich's Contract with America in 1994. Prior to that, politics were more congenial. It was possible to be political friends with people who were not a member of your faction or party without being considered a traitor. Congress used to be able to legislate, unlike today's gridlocks or fights to the death. There was a lot of horsetrading and compromise and then at the end of the day, everyone went out to dinner with each other. Romney is still upholding that tradition. So, yes, he can be friends with both Lee and McMullin. And, not wanting to endorse Lee, he is using that friendship as an excuse instead of calling Lee a shithead. Politics used to be more gentlemanly than it is now.