Winner Take All in the Republican primary means different things in each state. I’ve improved the estimates to make the spreadsheet more accurately reflect the rules.
New Jersey is what people probably think Winner Take All (WTA) means. The person who gets the most votes gets all of the delegates.
California, Indiana and Maryland are more typical. There is one statewide group that goes to the plurality winner of the entire state, then each Congressinal district (CD) has an independent WTA race. In some states, if the winner of the State wins with a majority (>50.0%), then the CD delegates become bound to the winner, also.
Right now, Donald Trump appears to be over the finish line, but that’s probably not true. South Dakota and Montana are true “winner take all” states, but there are not yet any accurate polls. Because Trump is ahead nationally, he is getting 56 delegates that are more likely to go to Cruz based on surrounding states.
On the other hand, Trump has a big lead in California. Even with CD WTA, you don’t need 100% of the vote to get most of the delegates. If Trump carries the state, he is likely to win most of the 53 CD races. On the other hand, by June 7th, it will be obvious Hillary has won, and independents are more likely to vote in the Republican primary.