Actually, he's not getting a large share. He seems stuck around 40 percent of the vote. He split with Cruz yesterday but, I believe Cruz edged him on delegates. Rubio took Puerto Rico today. Before you laugh. with 23 delegates, that's more than a number of states and Rubio got them all.
Trump has 391 delegates and the other 3 guys have 495. 12 more delegate groups get chosen in the next 8 days. Trump is backing down on some of his claims saying that, of course, he will have to obey the law. Right now, Trump has 44% of the delegates and 34 % of the votes cast. He has won 2 of the last 5.
The winner take all states are coming up. If Kasich can take Ohio and Rubio can hold Florida, then Trump has peaked. The "keep it split" plan will work. If not, then it gets uglier. Also, Trump hasn't done well in states that don't allow crossovers. It's so fluid now that the three day old article is like three day old fish.