It's very possible McCain is responsible for Flakes problems within his party. Many feel betrayed by him but voted for him in '16 so they do not want to make the same mistakes for someone who in their eyes could become more of a traitor, so they want Ward now. Kinda like how many Clinton voters now want the Clintons to go away.
I've been saying for months that Independents are not going to warm up to Flake just because he wrote a book to make him look like a maverick. I have never met one person here in Arizona, including my dearest home of the east valley where many are conservative/ independent, that likes Jeff flake. He's got the personality of an onion.
So Flake wouldn't be favored to win in a General as many previously believed. He trailed Romney which is well...yikes
Flake continues to look more vulnerable than Heller by the week.