Why would Bush speak at a Trump rally?
Well, I know how I'd do it.
"Hey, Yebbie, buddy, c'mere. See all those people out there? They're all for YOU, buddy! Yeah, that's your people out there, Yebster. Now you just wait until the guy with the funny hair finishes and go out there and knock 'em dead! Give 'em your speech about immigration, Yebbie! Yeah, that'll bring the house down!"
It would work, too. And with Yeb it might even work twice.