That is inspiring his efforts

"McMullin agreed that Trump seemed rattled by the recent criticisms from Tillerson, Corker and Barrack. “He probably understands their remarks represent a new stage of acceptance setting in across the country, even among his supporters, that he is unfit and incapable.

“That, I think, is inspiring his accelerated efforts to throw red meat to his base to shore up their support. I expect that to continue, if not intensify, and to result in increasing political challenges for the GOP as 2017 and 2018 elections approach and in years to come.”

(The Guardian.)

Does That in That, I think, is inspiring his accelerated efforts refer to their remarks represent a new stage of acceptance setting in across the country, even among his supporters, that he is unfit and incapable in the passage above?