His approval rating and confidence regarding handling the economy have really nose dived among Independents in recent months. That's the whole ball game. It really doesn't matter if we retake other Trump voters if those Independents have soured on him.
Last year for all the implosions by Trump and all the debate defeats and everything else, Independents remained loyal to him. It drove me nuts and made no sense but it always kept him in the ball game. The projections of a lopsided Hillary win were always idiotic because they ignored the Independent percentages and relied on Republicans remaining disloyal to their nominee, which was not going to happen.
As always...big picture. Short term overreaction is the worst mode to take. That's Happy Adjuster mindset.
There were several articles in recent days regarding Independents fleeing Trump. Other than logical suspects like Republicans and self-identified conservatives, the only huge block that refuses to budge from Trump is whites who lack a college degree. They still have a net favorable impression of Trump. Consequently every time an article shows up here proclaiming that the white working class aspect was overblown in regard to 2016, the only appropriate response it to laugh at it and mock it. It was not overstated and it's the reason Trump prevailed. People who deny that aspect are the same geniuses who take statewide poll numbers at face value with absolutely no clue regarding the foundational ideology of each state:
http://www.npr.org/2017/06/28/534602973/trump-fails-to-reach-beyond-base-as-independents-disapproval-grows