Like many Vox.com staffers, I live in the District of Columbia. Meaning that even though the laws of the United States of America apply to me, I don't get represented in the Congress where those laws are written. The editorial board of the Washington Post is quite a bit more conservative than I am, but many of its members also live in DC, as do many of its readers, and most of us feel that this is pretty unfair.
So when the Post editorial board sat down with Ohio Gov. John Kasich, they asked him about it and he offered a strikingly honest case against voting rights for the District: it has too many Democrats:
ARMAO: But you realize though that people in D.C. pay taxes, go to war and they have no vote in Congress.
ARMAO: How is that–
KASICH: Well look, I am not – I don’t – I am not, because you know what, what it really gets down to if you want to be honest is because they know that’s just more votes in the Democratic Party. That’s what–
ARMAO: So if there were Republicans in the District, you would have a different position?
KASICH: Yeah, okay, well look, they send me a bill, I’m president of the United States, I’ll read your editorials.
This would not be the first time partisan politics played a role in statehood decisions (the reason there are two Dakotas is that Gilded Age Republicans were trying to pack the Senate) but it's good to have clarity about the reason.
It also underscores the extent to which it's unfortunate that Democrats didn't try address this issue in 1993–1994 or 2009–2010 when they had a chance. Creating a new state that would include the populated areas of DC (leaving behind a rump Federal District containing the government buildings and national monuments on the Mall) would only require an ordinary act of Congress, not a supermajority to amend the Constitution.
Nobody should begrudge Republicans the right to act out of partisan self-interest, but the way the system is supposed to work is that the other party then needs to act out of its own partisan self-interest.