My take on Johnson’s percentage in the polls is that you’ll see that a lot in the summer - a third party candidate polling a significant percentage. They almost invariably fade after labor day.
Sure, Perot was different, but he’d been making his presence felt for months before the conventions, even leading the field for a bit before letting on that he was crazy as a bedbug. And not crazy in a ‘you gotta be crazy to think you can win’ way - crazy in a ‘Vietcong are coming to kill me and disrupt my daughter’s wedding!’ way.