Thus Tuesday, Pennsylvania, Maryland, Connecticut, Rhode Island, and Delaware hold their primaries for both parties. All are holding closed primaries, meaning only party members can vote.
The largest of these, Pennsylvania, has a particularly strange method. Most delegates are elected personally, not as a representative of a candidate. In other words, voters may vote for "John Smith, delegate from Altoona". Voters would have to know that Mr. Smith is a supporter of Ted Cruz as there is no indication of that on the ballot. Delegates elected this way are unpledged. This means, that even if Mr. Smith supports Cruz today, he could change his mind and vote for Donald Trump on the first ballot at the convention. As a result, candidates must carefully vet the people selected as their delegates, and then get the message to their voters to support those particular delegates. Although, Trump is favored in the State, this level of organization and planning may end up favoring Cruz. It will be interesting to see what happens.
In all of these State, many of which are winner take all, Trump is ahead by a good 15 to 20 points. He is likely to greatly increase his delegate lead, although the 1237 majority may still remain elusive.
On the Democratic side, Hillary Clinton also polls well above Sanders in all five States. If she does as well as polling suggests, she will continue to widen her lead, although still will not hit the needed majority of delegates until June.
Cruz, Kasich, and Sanders all seem resigned to stick it out until the Convention despite no realitsic path to winning the most delegates. Cruz seems to be hoping to prevent Trump from obtaining an outright majority and possibly picking up delegates on later votes. Kasich knows he is an extreme longshot at this point, having won only one state and not likely to win any others. He is hoping for some extreme event at the convention and for chaos to give him a shot. It seems very unlikely. Sanders does not expect the nomination at this point. He is mostly hoping to influence the Party platform and perhaps get a shot at a prime time speech at the convention.
The contests on Tuesday will likely tighten the noose around the challengers as the front runners continue to extend their leads. Still, the outright majority remains elusive for both leading candidates.
At this point, it seems clear Clinton will almost certainly be the Democratic nominee, and Trump very likely the Republican nominee. Both candidates have extremely high negatives. It will be interesting to see if a third party candidate sees blood in the water and decides to mount a serious campaign.