I would like to point out two things. First, there are still three months until the election, and anything can happen. Second, the article itself goes on to say that immediate post-convention numbers can be volatile. But I can't help thinking that all of Trump's blunders, plus the continual drip-drip-drip of Republicans defecting from his side, are mostly responsible. It is possible that Trump has reached a tipping point from which he cannot recover. Seriously, even if he suddenly became "presidential" this very moment...who'd believe it anymore?