Liz Mair is a straight-shooter. Yes, she's a Republican and she's worked as RNC online communications director in the past, but I have followed her for eight years and she has always, always been honest about what she sees.
Her appearance on Anderson Cooper's show was no exception. When asked by Cooper about Trump's messaging, Mair laid it out there straight, and told Cooper that Trump's "message is being a loudmouthed dick."
She was unapologetic afterwards, too. It's a feature, not a bug.