For all of the drama and excitement surrounding this year's Republican nominating contest, where gaffes and attacks can command a top headline, the fact that there was an actual contest, today, has been mostly underreported. The New York Times election page didn't include it along with news of the Democratic campaign in 2016 Maine Democratic Caucus, and fivethirtyeight's main article was on Peyton Manning's career.
There is one good reasons for this: first, the residents of Puerto Rico can't actually vote for president. Although they have a say in the primary, they have no vote in the actual election. But there are a few good reasons why the Puerto Rico vote is important. First, it was won decisively, with Marco Rubio winning 70% of the vote. This makes it the first state to be won by a majority, even if it isn't a state. This is an important win for Marco Rubio, who despite there being some consensus that he is the most viable candidate, has less than half as many delegates as either of his main rivals. Minnesota and Puerto Rico aren't usually the power axis in Republican contests, but it shows that Rubio may have some areas he is stronger in.
It is also a reminder that the struggles that define much of electoral politics are not universal across all of the United States' 50 states and 7 territories. If the battle between Trump and Cruz is one of (to put it simply) nationalist anger against religious zeal, there are plenty of areas in the United States where the issue is not of importance. Rubio's success here means he might have success in areas like the Pacific Coast and upper midwest where many of America's stereotypical fracture lines are not at the front of people's minds. We might see evidence of this on March 8th, when four very disparate states, Hawaii, Idaho, Michigan and Mississippi all vote.