CNN:
With 16 primaries and caucuses remaining, Donald Trump has to win 70% of the delegates to secure the 1,237 needed to win a first ballot at the Republican convention. Several states are coming up that are more favorable territory for Trump than Cruz, especially New York and Pennsylvania where Trump still has significant leads.
Even so, winning more than two thirds of the remaining delegates is a daunting challenge for him. In the 36 primaries and caucuses leading up to Wisconsin, Trump won only 46% of the delegates. And now he heads down a tough homestretch with Cruz seizing the momentum....
CNN h/t FreeRepublic