The rap on Ted Cruz has been that his strength is limited to (1) caucus states and (2) states with large proportions of evangelical Christians. But Cruz undid that analysis with his double-digit victory over Donald Trump in Wisconsin last week.

Cruz beat Trump 48 percent to 35 percent in a primary election (so much for the caucus argument). And he did so by besting the New York billionaire among virtually all groups, whether defined by income, age, or educational attainment. Trump did manage to win, by 9 points, that quarter of the Wisconsin GOP primary voters who described themselves as moderate or liberal; but Cruz beat Trump by 21 points with the remaining three-quarters who described themselves as somewhat or very conservative.

With a broad-based win in Wisconsin, Cruz demonstrated he has a realistic path to winning the GOP nomination at an open convention. If Cruz can win a handful of key Midwestern and Western states—Indiana, Nebraska, South Dakota, Montana, and California—he can keep Trump from getting the majority of delegates that are needed to win the nomination.

Here's what to watch for as Cruz and Trump face off in the 16 states that have yet to vote.

April 19: New York (95 delegates)

Trump is on track to score a big win in his home state. The only question is just how big it will be. As we went to press, Trump was at 53 percent in the Real Clear Politics average of New York polls, with John Kasich and Ted Cruz each more than 30 points behind. In New York, a candidate gets 14 delegates if he gets 50 percent of the statewide vote (those delegates are awarded proportionally if no candidate hits 50 percent). Each of New York's 27 congressional districts awards three delegates. If someone wins 50 percent in a congressional district, he gets all three delegates. If the winner is below 50 percent, he gets two delegates and the runner-up gets one.

The goal for Trump's opponents in New York will be to keep him under 50 percent in as many congressional districts as possible. Trump could walk away from New York with more than 90 delegates, but it's possible he could be held to fewer than 75. (Even that small of a difference could make or break Trump's effort to go into the convention with at least 1,237 delegates.) It's been difficult to knock Trump's share of the vote down from what he was getting in polls a week or two out from a given state's election, but it has happened in a couple of states, such as South Carolina and Iowa.

April 26: Connecticut (28 delegates), Delaware (16 delegates), Rhode Island (19 delegates), Maryland (38 delegates), Pennsylvania (71 delegates)

Trump is expected to romp on the East Coast. In Connecticut, a big question is whether Trump can be held under 50 percent of the vote (in which case he would likely earn about 20 delegates) or whether he wins more than 50 percent and takes all 28 of the delegates. Trump is also likely to win Delaware's pure winner-take-all primary, but he'll split delegates in Rhode Island, because they're awarded proportionally.

Trump is favored in Maryland, which awards delegates on a winner-take-all basis both by statewide and congressional district vote. A Washington Post/University of Maryland poll conducted just before the Wisconsin primary showed Trump leading John Kasich 41 percent to 31 percent in Maryland, with Cruz in third at 22 percent. There's a chance that anti-Trump voters will rally around the candidate most likely to beat Trump. If not, Trump will win all but two or three of Maryland's eight congressional districts.

That leaves Pennsylvania, the most important state voting on April 26, and one whose decidedly quirky rules may muddy the results. Seventeen of Pennsylvania's delegates are awarded to the winner of the statewide vote. But the remaining 54 are elected by congressional district. And in choosing those delegates, the names on the ballot are not those of the candidates but of the delegates. The ballots will not list which presidential candidate each delegate supports.

Some of the would-be delegates in Pennsylvania have publicly announced the presidential candidates they back; some say they'll back the candidate who wins the popular vote in their congressional district; and some have refused to give any indication whom they support. In any event, those directly elected delegates will head to the convention officially unbound to any presidential candidate: They can vote however they see fit.

The latest Quinnipiac poll of Pennsylvania, conducted just before the Wisconsin primary, showed Trump leading Cruz 39 percent to 30 percent, with Kasich in third place at 24 percent.

May 3: Indiana (57 delegates)

May 3 is one of the most critical dates left on the GOP primary calendar. Will two weeks of Trump victories on the East Coast give him momentum as the race returns to the Midwest, or will Cruz be able to re-create his Wisconsin victory? The answer will go a long way in determining whether Trump can be stopped.

Indiana will award 30 of its delegates to the winner of the statewide vote. The remaining 27 delegates will be divvied up among congressional districts and awarded on a winner-take-all basis.

There haven't been any public polls of Indiana, but the state's demographics and political culture suggest Cruz is the slight favorite. One complicating factor is whether John Kasich remains in the race. The favorite son of Ohio, next door, Kasich could enjoy enough regional popularity to split Indiana's anti-Trump vote with Cruz, handing the state to Trump.

May 10: Nebraska (36 delegates), West Virginia (34 delegates)

Nebraska's winner-take-all primary is a must-win for Cruz, and he seems well-positioned for a victory there given his strength in the region (he beat Trump by 25 points in the Kansas caucus). But Trump is strong in Appalachia: He's expected to sweep West Virginia's delegates (25 go to the statewide winner, with the remaining 9 split among the state's three congressional districts).

May 17: Oregon (28 delegates)

Oregon is one of the least important states left in the GOP race, because it awards its delegates proportionally. A 20-point victory in Oregon would only give the winner six delegates more than the runner-up.

May 24: Washington (44 delegates)

The rules are more complicated in Washington state. Fourteen delegates are awarded proportionally based on the statewide vote. The remaining 30 are split up among the state's 10 congressional districts. If a candidate gets more than 50 percent of the vote in a congressional district, he gets all three delegates. If the winner gets less than 50 percent, the delegates split, with two to the winner and one to the runner up. However, if there are three candidates above 20 percent but below 50 percent, each candidate gets one delegate.

Cruz is likely to do well in the more conservative eastern part of the state while the western part of the state will be more competitive.

June 7: New Mexico (24 delegates), New Jersey (51 delegates), South Dakota (29 delegates), Montana (27 delegates), California (172 delegates)

Given the number of twists and turns in the two months since the Iowa caucuses, who can say what the GOP race will look like in two months, on the critical final day of primaries? Will Kasich remain in the race? Will debates, events, or new revelations about the candidates shake things up?

Right now, given Trump's strength in New York, it seems likely that he will win New Jersey's winner-take-all primary, while Cruz would seem to have the advantage in the winner-take-all Montana and South Dakota primaries. New Mexico, like Oregon, is less consequential because it awards its delegates proportionally.

The real wild card—and the most important state left to vote—is California. The state will award more delegates than Ohio and Florida combined, but just 13 of them will go to the winner of the statewide vote. The remaining 159 delegates will be split equally among the state's 53 congressional districts. The winner of each district gets its three delegates.

A recent Los Angeles Times poll showed Trump leading Cruz by just one point, 36 percent to 35 percent, with Kasich at 14 percent. A Field poll of California showed Trump doing better and leading Cruz 39 percent to 32 percent, with Kasich at 18 percent. But that same Field survey showed Cruz holding an 11-point lead in Los Angeles County, where 18 congressional districts are located, and a 9-point lead in the Central Valley, home to another 8 congressional districts.

If Cruz wins Indiana, Nebraska, Washington, South Dakota, and Montana, then merely splitting delegates evenly in California with Trump would be enough for Cruz to keep Trump some 75 delegates short.

Even then, Trump could win the nomination at the convention on the first ballot—if he secures enough votes from the 150 to 200 unbound delegates. But the vast majority of unbound delegates, elected by conservative activists and party loyalists at GOP conventions, are likely to back Cruz. Daniel Nichanian, a University of Chicago Ph.D. candidate tracking unbound delegates, has found that just two of them currently support Trump publicly. Most unbound delegates from North Dakota and Louisiana have already indicated they're for Cruz.

And as Robert Eno of Conservative Review has reported, 58 of Kasich's delegates would become unbound if he drops out of the race before the convention. Selected by conservative activists and party loyalists, those Kasich delegates would be unlikely to support Trump.

We may not know how the primary is going to play out, but we do know this: Donald Trump is far from having a lock on the nomination.

John McCormack is a senior writer at The Weekly Standard.