Under what scenario(s) will Trump crash the 2016 GOP party, and turn out the lights?

Last month, The Donald made a point to humiliate the oafish dunce Reince Priebus, and staged a circus act at Trump Tower where he "pledged" not to run as an independent.  If you have ever read "The Art of the Deal" you get some insight into the soul of a man who views such calculated tomfoolery as a mere bargaining point.

So under what circumstances will Trump run third?  He will most probably do it if JEB! Bush and Hillary Clinton are the nominees of their respective parties.  The temptation would be too great.  He would likely outperform Perot (by at least a few points) and could proclaim he was the strongest independent since Teddy Roosevelt in 1912.  He could also push JEB! Bush into being the worst performing Republican nominee (in terms of the popular vote) since Taft in that same year.  Worse than Herbert Hoover, worse than Barry Goldwater.  Sweet revenge for an insecure plutocrat.

Would he do it under any other scenario?  If Bush faced Biden, or Sanders?  Probably not Sanders. A Sanders presidency is simply too much of a threat even to Donald Trump's material fortunes.

More importantly, would Trump do it if Rubio faced Clinton? That is the real question of day. After all, does The Donald really want a "lightweight" in the White House?

New York Times: Donald Trump Is Not Going Anywhere