The instances described above, of the US federal government and US subnational actors taking on independent (and somewhat oppositional) roles, do not map perfectly onto the US partisan divide. Some of the entities that have committed to Paris targets are run by Republicans. Certainly some of the states Canada will be negotiating with are red states.
But the mapping is, let's just say, a little too close for comfort.
Much has been made of the "big sort" that has divided the US into two polarized, partisan camps. That division has inscribed along various fault lines — minority versus white, educated versus not, rich versus poor, young versus old, ordinary versus elite — but the most salient, the one that does more explanatory work than any other, is urban versus rural and exurban. (Will Wilkinson has done stellar work on this; start here.)
Big cities tend blue; liberals tend to live in cities. The reason Democrats can get a popular vote majority and still lose the presidency is that they cluster in cities while Republicans spread out, covering more land and thus, based on America's absurd and archaic system of government, accruing more power.
Red America now has the federal government, 33 governorships, and unified control over 32 legislatures. Republicans have a total of 68 state legislative chambers to Democrats' 31.
Blue America has 16 governorships but total control over state government (governor and legislature) in just five states: Hawaii, California, Oregon, Connecticut, and Rhode Island. But Blue America has cities — almost all the big ones.
At least currently, Blue America has more people but less political power. That's partly what the subnational organizing is responding to.
It is often said, metaphorically, that America is becoming two separate countries, with different values and visions, occupying the same territory. But what if that becomes less metaphorical?
What will happen when Red and Blue America starting thinking of themselves as separate countries, and acting that way, consolidating their power and negotiating independently? What happens when they really start fighting?
It's a little dystopian, as it carries the whiff of a second Civil War. But as we've learned about dystopias this past decade, they need not happen all at once, dramatically. They can happen in creeping increments, each of which allows for enough of a pause that it comes to seem normal.
Right now it's all fun and games. It's only Canada. It's only a voluntary climate treaty. Blue and Red America are not, as yet, wielding conflicting legal authorities, getting involved in internal economic or trade disputes, or seeking explicitly to fight or punish one another.
But how long will that last? How long before open (or at least more open) hostilities?
The federal government could deny California its waiver under the Clean Air Act, denying it the right to set its own fuel economy standards. Rick Perry could use his bogus grid study to declare emergency powers and override local decisions to close coal plants. Some blue town in a red state could build its own self-sustaining microgrid, form a municipal utility to run it, and declare itself independent of state and federal authority over electricity.
And those are just energy disputes. If you want to get really freaky, imagine if Trump tries to start some ill-advised war or implement some police-state security measure and city governments band together to refuse to participate. What happens then?
I have no idea. I can spin fanciful scenarios all day, but I've given up on prognosticating.
Still, I can't imagine that having two parallel governments operating in the world's most powerful country is going to stay peaceful and symbolic for long. Red America — especially in its intemperate and vengeful current incarnation — is going to notice that Blue America is being hailed as an international hero for saving the US commitment to Paris. It's going to notice that Canadian officials are spending an awful lot of time with mayors. It's going to notice subnational climate and trade agreements forming under its nose.
Trump is going to notice that even though he won the presidency, the world keeps talking to the governors and mayors who oppose him. I worry it will not end well.