My take, Badcat, is that Republicans began fighting back under 2015 under Trump. Before then, any Republican leader - and I mean ANY such leader - could be reviled, hated, loathed, and called a racist, xenophobic, bigoted, woman-hating murderer and that was hunky-dory.
We were told hundreds of times by (D) politicians that Ronald Reagan was an imbecile, a fascist war-monger, would take away health care from babies, despised women, hated black people, supported slavery, etc. George HW was an imbecile, a fascist war-monger, would take away health care from babies, despised women, hated black people, supported slavery, etc. George W. was an imbecile, a fascist war-monger, would take away health care from babies, despised women, hated black people, supported slavery, etc.
Trump? Pfft, he is an idiot Hitler but worse. Deranged, unhinged, a Russian agent, intent on killing Americans to benefit himself financially. Not that there's anything wrong with the latter thing, (D)imbos admit, but still ...
Then Trump responded in kind, and it was, "WHAT HAPPENED TO DECORUM?!?!?"