For a nation primarily born out of a taxation dispute with its colonial over-lord, the US has had something of an ambivalent approach to imperialism ever since. So it is then that The Land of the Free doesn’t seem to apply to both Puerto Rico and Washington D.C in the way that it does to the regular 50 states of the Union. (The same is also true of the likes of Guam and American Samoa – discussions for another time.)
The issue of Puerto Rico and statehood was jarringly brought into perspective once more in the wake of the devastating impact of Hurricane Maria in late 2017. Trump’s dismal visit to the island to “address” that problem, was akin to that of a late nineteenth century European monarch’s superficial and disinterested excursion to a far-flung part of their overseas empire – arrogant, uncalled for and devoid of human decency. 
Nearly 3.5 million US citizens live in Puerto Rico. Despite that, they have no representation in Congress and while many are not obliged to make a federal tax return each year, they are still American taxpayers. “They pay payroll taxes, business taxes, and estate taxes. They helped pay for disaster relief in Texas after Hurricane Harvey and in Florida after Hurricane Irma.” 
The reality is, Puerto Rico is a hang-over from the late nineteenth century Spanish-American war. While liberated Cuba eventually broke free of American rule, Puerto Rico, swept up by the US during those hostilities, has never been afforded the luxury of anything else other than subsequent semi-colonial status.
The traditional role of the US being a full-throated advocate for democracy and being a role model for newly decolonized countries around the world, particularly so post World War Two, is fundamentally undermined by its current relationship with Puerto Rico. Sadly, there is also a questionable undertone of race that can be read here – the subservience of a Hispanic / Latino demographic to that of white America. That is absolutely unacceptable.
It’s not too far removed from the irony of the British and French calls their occupied colonies to fight Axis, to throw off the yoke of occupation, only to then have British and French imperial order restored at the end of the War. Where was the liberty in that and where is the liberty for Puerto Rico being freed from rule from Madrid only to have it re-imposed by Washington?
Which neatly brings us on to…Washington D.C.
With even heavier irony, Washington D.C. finds itself in a similar predicament. Home to over half a million US citizens, sharing the full tax burden array as the rest of the regular US. It is a significant world capital that bizarrely finds itself devoid of Congressional representation.
Former President Barack Obama came out with his support for statehood for DC while in office, back in 2014.
“Folks in D.C. pay taxed like everybody else, they contribute to the overall well-being of the country like everybody else, they should be treated like everybody else…There has long been a movement to get D.C. statehood and I’ve been for it for quite some time. The politics of it end up being difficult to get through Congress, but I think it’s absolutely the right thing to do.” 
Both Puerto Rico and D.C. have voiced strong support for securing statehood. In a nonbinding referendum in 2012, Puerto Ricans voted in favor of becoming a fully-fledged state.  In 2016, voters in D.C. overwhelmingly supported statehood for D.C., becoming the state of “New Columbia”, also in a non-binding vote.  Both are still of course waiting.
Just why though should the four million or so American citizens of Puerto Rico and D.C. continue to wait? Democracy is at the heart of the Great Republic and to continue to deny statehood and full political representation to is to make a mockery of the claimed democratic credentials of the US. It doesn’t matter whether if it is four, four million, or forty million without full representation – wrong is still wrong on any scale.
The concept of “no taxation without representation” brought British colonial rule to an end in the late eighteenth century but seemingly isn’t applicable to either Puerto Rico or Washington D.C.
The ghost of the George the Third must be raising something of a spectral eyebrow about that.