I think your Trump-Palmer comparison is decent, but not sure about McConnell. Something that seemed key to Abbott was his focus on very repetitive and simple statements - the three word slogans (stop the boats, axe the tax; hardly discouraged "ditch the witch"). Not saying there hasn't been similar before, but he was particularly effective with it. Trump has used similar tactics (build the wall, lock her up, etc), which might've encouraged OP's point.