* Clinton need just 18% of the remaining uncommitted delegates (pledged and super) to win the Democratic nomination. Almost all of the Democratic contests remaining are proportional.
It is virtually impossible for Sanders to become the Democratic party nominee at this point. It will take her until June 7, for her to seal the deal. But, by then, she will need only about 11% of the delegates remaining (or less) to cinch the nomination. In polling, Clinton and Sanders are currently neck and neck, and I can't think of any primary that Sanders has won by an 82-18 margin. Clinton can direly screw up once or twice in the next month and a half and still win out of sheer force of inertia.
Her odds of winning the Democratic nomination at this point are well in excess of 95%. Maybe 97-98% would be more realistic. In all likelihood, she will win the race for pledged delegates handily, in addition to dominating the ranks of the super-delegates and winning the "popular vote."
* Trump has 988 delegates after today and he needs 1237 (249 more). So, he needs about 43% of the remaining delegates, which would be a problem except that he is a decisive front runner in West Virginia, New Jersey and California, has a narrow lead in Indiana, and is likely to pick up a few extra delegates here and there, at least in the few states that award GOP delegates proportionately.
Trump may not have the cakewalk that Clinton has ahead of her for the remainder of the primary season. But, he can manage to be a fairly mediocre front runner and still cinch the nomination on a first round vote with pledged delegates alone.
And, it stands to reason that a front runner in the primary and caucus process nationwide is going to be so hated in Cleveland that he can't wrangle at least some uncommitted delegates. So, he can actually still win in the first round with some undetermined number of delegates less than 43% of those remaining. Certainly, Trumps path to the Republican Presidential nomination is much more straightforward than it is for anyone else.
Cruz needs a miracle. It is mathematically impossible for Cruz to win in the first round with the support of his pledged delegates even if Cruz wins every single remaining delegate in every single GOP primary remaining. The only shot Cruz has is to receive massive defections of pledged candidates in his favor in a second round of convention voting, and it isn't at all obvious that this would go his way in a two way race between Trump and Cruz who are the only two candidates even eligible to run under current GOP rules that are unlikely to be changed this year.
Trump needs a few weeks that don't absolutely suck.
Trumps odds of winning the Republican nomination are about 75%, with Cruz at about 20% and everyone else combined at less than 5%. Indeed, those numbers are probably unduly hard on Trump and too favorable to Cruz and unnamed white knights. Maybe the real numbers are more like 85%-13%-2%.
Also, any Cruz win must entail what amounts to a GOP establishment coup. Trump is pretty much guaranteed to have a plurality of the delegates and votes going into the convention.