The polling of the upcoming contests shows Trump with significant leads in all states where there are polling results. Trump has at least an 8% lead in polling averages for all remaining states with polling results. Trump appears to have very big leads in Arizona (58), New York (95), New Jersey (51), and California (172). The potential is there for Trump to win all 376 delegates. Adding to his current 695 would be 1071. 1237 is needed to win. There are 628 delegates in the other contests outside the four mentioned. Most of those have proportional allocation. Trump would only need about 26-27% of those delegates.
This article is an summarization of the numbers and the situation.
Republican leaders adamantly opposed to Donald J. Trump’s candidacy are preparing a 100-day campaign to deny him the presidential nomination, starting with an aggressive battle in Wisconsin’s April 5 primary and extending into the summer, with a delegate-by-delegate lobbying effort that would cast Mr. Trump as a calamitous choice for the general election.
Recognizing that Mr. Trump has seized a formidable advantage in the race, they say that an effort to block him would rely on an array of desperation measures, the political equivalent of guerrilla fighting. NOTE- Mitt Romney already came out very strongly against Donald Trump but that effort appears to have done nothing to slow down Trump's run to the Presidential nomination.
538.com (number and poll guru Nate Silver's website) has Trump currently at 695 delegates
538.com has Trump as 91% likely to take the 58 delegates in the winner take all Arizona primary
Arizona, Montana, South Dakota, Nebraska, New Jersey and Delaware are winner take all.
Trump has a 28.5 to 18.5 lead in the most recent Wisconsin polling.
Trump leads New York polling by 58.8% to 11.2%. Delegates in New York are allocated proportionally, but with a winner-take-all trigger. This means if a candidate gets over 50 percent of the votes, they are assigned all the delegates.
Trump leads Maryland polling 33.4 to 24.6.
Trump leads California polling by 30.5 to 20.6 for the most recent 9 poll average. The most recent poll Trump leads 38% to 22% and 20%.
California's system is essentially winner-take-all but with modified rules. The delegates are split between congressional delegates and state-wide delegates, with three delegates assigned to Republican National Committee officials. The top candidate state-wide picks up 10 delegates, while the top candidates in each district pick up three votes per district. Indiana and Wisconsin follow a similar method of distributing their delegates.
Trump leads the polling in Pennsylvania 32.4 to 15%
Trump has a 35.5% lead to single digits for Cruz and Kasich in New Jersey