A referendum on the political status of Puerto Rico was held in Puerto Rico on June 11, 2017. The referendum had three options: becoming a state of the United States, independence/free association, or maintaining the current territorial status. Those who voted overwhelmingly chose statehood by 97%
https://en.wikipedia.org/wiki/Puerto_Rican_status_referendum...
; turnout, however, was 23%, a historically low figure.[3] This figure is attributed to a boycott led by the pro-status quo PPD party.[4]
In the US, if only 57% of people vote, you could say our president is only elected by less than about 30% of the people with the popular vote, half the eligible voters or about a third of the country.
[1] https://en.wikipedia.org/wiki/Voter_turnout_in_the_United_St...
[2] https://en.wikipedia.org/wiki/United_States_midterm_election
In this case, Congress would need to make the decision that is in keeping with the "people of Puerto Rico". If you read further in the referendum link you posted, there are a number of reasons why the referendum was boycotted.
I doubt that Congress would want to jump into the middle of such an ambiguous situation and declare Puerto Rico a state by fiat.
If you are saying that because PR had a boycott and some didn't vote that the vote is a fraud, then you could say the same about ANY vote in the US because people boycott or don't vote because they don't believe in the system or think it is rigged etc or many other reasons.
That is why you have to vote, boycotting votes is not smart, probably the worst use of a boycott ever as it takes your power away. Usually boycotts are to gain power i.e. not purchasing from a certain company. Boycotting a vote isn't even worth mentioning, it is just not smart.
Your comment here about "people don't vote all the time for different reasons" doesn't amount to the situation in PR at all. It's significant, and to ignore it is dishonest.
Whether you believe a boycott is "smart" or not.
The Puerto Rico statehood referendums are not undertaken pursuant to any law and are not binding. It's like the government of Maryland holding a referendum on secession from the U.S. If only a quarter of eligible voters show up, that doesn't mean that everyone else wants to go along with the minority. It means that the majority don't see the effort as legitimate in the first place. (There is a reason why people would view the 2017 referendum as illegitimate. The ballot was biased against the non-statehood options, e.g. calling Puerto Rico's current status that of a "colony").
The politics of integrating Puerto Rico are likely impossible to make it happen anyway.
The 2012 referendum, in contrast, had 78% turnout. 46% voted to retain the current arrangement, and another 21% voted for either free association or full independence (i.e. increased sovereignty--the opposite of statehood).
A better stance to take might be: "We need to reiterate to the citizens of Puerto Rico that they are perfectly free to opt for statehood, or independence at any time."
That's not how voting works, though...
I'm commenting on "voting" in general there, not specifically the referendum. But even with 100% turnout, there's no legal mechanism for Puerto Rico to force Congress to act.