Does this forum ALWAYS overestimate candidates who don't run? He'd be polling around 10% at best. He'd be scooping up a bunch of people saying they'd vote for Johnson/Stein as a protest vote, and not much beyond that.
A very well recognized and experienced candidate who has enough cash needed to run a substantial campaign should do significantly better than Johnson, who is consistently polling around 10%. He would be able to pick up some people from both major parties since their nominees are so disliked and he is moderate.
Johnson isn't polling at 10%. "Other" is polling at 10%.