But you have to hand it to him, he has popularity at 87% among Republicans, the second-highest in history for support in your own party.
Trump certainly has a core of blindly loyal supporters. But there's an additional factor at work here. The Republican Party is shrinking as traditional conservatives and moderates disavow racism, xenophobia, misogyny, fiscal irresponsibility and trade barriers. So little by little, all that's left are Trump supporters. It's no surprise then that 87% of Trump supporters are Trump supporters. But they still only comprise around 40% of the electorate.