When Marco Rubio attacked Donald Trump on the debate stage this week for using undocumented Polish workers to build Trump Tower, the developer shrugged it off. "He brings up something from 30 years ago," Trump shot back. "It worked out very well. Everybody was happy." But a look into the history of the Trump Tower, the crown jewel of the real-estate mogul's empire, reveals the beginnings of the 68-story building were, in fact, rooted in the back-breaking labor of 150-odd Polish immigrants — most working illegally, some without full pay. "It's constructed on the blood, sweat and tears of the...