The split between Mr. Cruz and Mr. Kasich is always tough to predict. But in general, the Cruz/Kasich vote breaks along the lines of cultural liberalism and conservatism. Mr. Cruz does better (and Mr. Kasich does worse) in areas with more evangelical Christians, more white Republicans and fewer people with postgraduate educations. Mr. Cruz also does better in areas that look more like the “traditional” Republican Party — conservative areas with more families and married couples and people whose heritage is Protestant northwest Europe.

Many of these factors have hurt Mr. Cruz in the blue states of the Midwest. He has often finished third in more liberal places like the Detroit or Chicago metropolitan areas. It’s also why he’s poised to fare poorly in the Northeast.

But Mr. Cruz has not had this problem in less liberal metropolitan areas in the Midwest, like Milwaukee; Grand Rapids, Mich.; Kansas City, Mo.; and St. Louis, or in medium-sized cities in central Illinois like Springfield, Peoria, Bloomington or Champaign-Urbana. Mr. Kasich was no threat to Mr. Cruz in these areas, and indeed Mr. Cruz wound up beating Mr. Trump in most.

The Indianapolis area is somewhat more like Milwaukee, St. Louis, Kansas City and Grand Rapids than Detroit or Chicago. Most obviously, the Indianapolis area — and the state of Indiana — is conservative and tends to vote Republican. That’s underpinned by the demographic characteristics of the state: It’s more evangelical, less educated and, in particular, has fewer people with postgraduate degrees.

The tilt toward evangelicals and conservatism should allow Mr. Cruz to do better in Indiana than he did in Illinois or Michigan. It could be more like Missouri, which was almost a tie, or North Carolina, where Mr. Trump won by a slight margin. Mr. Trump also won by a slight margin in Illinois outside of the core of the Chicago metropolitan area.

That might still seem like a bleak precedent for Mr. Cruz. But the upside for him is that all of those contests occurred before Marco Rubio left the race. The results in Utah and Wisconsin suggest that many of Mr. Rubio’s remaining voters broke to Mr. Cruz. In Wisconsin, it was probably most of them.