However, if Mr. Cruz can consolidate the non-Trump vote in Indiana over the next week, he has a real, though by no means certain, chance to squeeze past Mr. Trump. A Cruz victory in Indiana would be enough to make Mr. Trump an underdog in the fight for 1,237.

In exchange for supposedly not trying in Indiana, Mr. Kasich is to get New Mexico and Oregon. In a way, this is counterintuitive: Mr. Cruz has fared very well out West, and he might have been favored to win either or both states over Mr. Kasich and Mr. Trump. Mr. Cruz’s concession would seem to increase the chance that these states go to Mr. Trump.

But even if this happens, it’s not a huge problem for the anti-Trump forces, at least from a delegate perspective. That’s because New Mexico and Oregon award their delegates on a purely proportional basis — meaning they award their delegates in proportion to a candidate’s statewide share of the vote. (Many “proportional” Republican states award two delegates to the winner of each congressional district and one to the second-place finisher.) They’re also two of the smallest contests remaining after Tuesday.

Victories are nice, but what matters for Mr. Trump in New Mexico and Oregon is his share of the vote, something that Mr. Kasich and Mr. Cruz’s arrangement should do little to change.