I'll go even further: find a way to grant them all the rights of citizenship (representation for their taxation) and let them decide for themselves on statehood. If there's any downside (I honestly don't know, maybe there is?), those people should be given the choice to determine their course of action for themselves.
But I agree completely, having people who pay taxes and can't access all the machinery of government they fund is criminal. (This also includes disenfranchised felons, but especially disenfranchised ex-felons.)
I think we're maxed out on this thread for who to enfranchise, which is good!
I believe one of the big downsides for citizens of Puerto Rico that has caused issues with the push for statehood is that they don't currently pay federal income tax. So it isn't exactly a taxation-without-representation situation, but they are obviously at the mercy of the US in many ways and don't have access to all of the levers of power that are available to others.
Witness the suffering at our delay in suspending the Jones Act (requiring two days of debate) during the Hurricane Maria relief campaign.
I doubt that Puerto Rico's lot would fundamentally change if they were a separate country though, they would still be largely at the mercy of their main trading partner and dominant regional power (the US).
I was also thinking of felons in my earlier comment, but it didn't quite fit my narrative. I don't find the rationale that they would just vote for there to be no laws particularly compelling.
But I agree completely, having people who pay taxes and can't access all the machinery of government they fund is criminal. (This also includes disenfranchised felons, but especially disenfranchised ex-felons.)