During a speech in Cincinnati, Trump suggested Democrats were "un-American" because they did not full-throatedly embrace his address to a joint session of Congress last week.
"They would rather see Trump do badly, okay, than our country do well," he said."It's very selfish. And it got to a point where I really didn't even want to look."
"They were like death and un-American. Un-American. Somebody said, 'treasonous.' I mean, yeah, I guess, why not?"
"Can we call that treason? Why not? I mean, they certainly didn't seem to love our country very much," he added.
Trump has falsely boasted that his generally well- received speech had the highest television audience numbers in history.
But Nielsen ratings show that three of Trump's predecessors surpassed his audience numbers during their first time giving the high-profile speech before Congress.
Trump did see a slight bump in the polls however, with his Gallup approval rating edging up two points to 40 per cent, its highest level in months.