Yes, it’s a Republican, there’s no need to respond to that part of the tweet, just the bottom half:

Sen. Johnny Isakson (R-GA): “Anybody who in any way tarnishes the reputation of John McCain deserves a whipping. Because most of the ones who would do the wrong thing about John McCain didn’t have the guts to do the right thing when it was their turn.” https://t.co/GAs2gJSdFa pic.twitter.com/DMG3etPPpM

— CBS Evening News (@CBSEveningNews) August 27, 2018