He seems to be the glue that's holding together the current coalition. The fascist project set is absolutely there, but they've never really won over the MAGA crowd who flocked to Trump's rallies. It's certainly possible that someone will manage to hold them together post-Trump, but nobody in conservative leadership right now seems to have his charisma and ability to draw those people in. (I absolutely believe that Vance thinks he can do it, but I am extremely skeptical.)

Which does make it challenging for them, since Trump's an elderly man who doesn't look to be in particularly good health.