Puerto Rico is the 29th most populated state/territory in the country. They basically have the same number of citizens as Connecticut. It would _definitely_ make a difference for one of the parties - though it would likely be the Democratic Party. However, Puerto Rico has been voting on statehood for a very long time and has historically voted against it. In the past couple years they did vote for statehood - twice in fact. But they did so while republicans controlled congress and since republicans know giving Puerto Rico statehood wouldn't benefit them they will never prioritize it while in-power.