In 2008-9 Republicans did not even make the pretense of Obama being a threat to democracy. (Which would have been absurd in a way it isn't for Trump, who tried to overthrow an election he lost.)
I remember when some lady called Obama "Muslim" (in the same tone of voice as she'd say "demon" or something) and Mitt Romney took the microphone from her and said "no, no, we disagree politically but he's a good man."
Shows how poorly those politicians understood the constituency they were fomenting. He was boo'd for it by people that had come to see him specifically, and about 15 years later, republican voters built a scaffold outside the Capital they were breaking into while chanting about hanging the Republican vice president.
I feel like American politicians often play with fire without understanding its nature as something that burns.
Trump is well outside the norms of POTUS's through history.