“If Donald Trump loses in Wisconsin next week, he will need to win roughly 60 percent of the remaining delegates to win the Republican presidential nomination outright — a daunting but not impossible challenge,” Politico reports.
“But if he fails to achieve it, and is thus unable to win the nomination outright, Trump is poised to suffer an exodus of delegates at a contested convention.”
New York Times: How votes for Trump might not turn into delegates.

