The Atlantic goes over the Republican presidential primary to be held in Puerto Rico this Sunday and how it could have a big impact in the primary race. The fact that Puerto Rico is a majority-takes-all delegates race, adds incentive for candidates like Marco Rubio and Ted Cruz to want a big win, although so far, none have actually made a major campaign effort there.

Like other Americans, Puerto Ricans are concerned about their economy, and their health care. But these national challenges have become acute crises in Puerto Rico. The issue of statehood also looms over the race.

Those challenges might provide one of the few remaining pathways for candidates not named Trump in the Republican primaries. With the road to nomination likely requiring a massive surge for Senator Ted Cruz or a dramatic turnaround for Senator Marco Rubio, Puerto Rico’s 20 at-large delegates are suddenly a tempting prize. Like several other early Republican contests, Puerto Rico is a majority-takes-all primary, in which delegates are assigned proportionally if a candidate wins a plurality of the vote—but when a candidate takes more than 50 percent, they take all the delegates. Unlike those other primaries, Puerto Rico has a history of landslide-majority victories. Mitt Romney took home all of Puerto Rico’s delegates in 2012, as did Senator John McCain in 2008.

Stay tuned for our coverage of the race Sunday as the presidential primary gets underway in this unpredictable election year.