Dear Mr. Trump, I challenge you to a duel over arguments about immigration. I am throwing the gauntlet at you because none of your competitors in the presidential race ever will. Jeb Bush co-authored a book about our immigration crisis. He acknowledged that the system is dysfunctional, but he did not dare to draw the only logical conclusion from the facts that he presented: that our immigration crisis has been caused not by foreigners but by our nonsensical immigration policy. Marco Rubio was in the group of eight trying a rational approach, but they also lacked courage to confront the problem head-on and produced a convoluted proposal that Rube Goldberg would be proud of. A few years ago, Scott Walker talked reasonably about our immigration problems. He backed off just before joining the presidential campaign.