To me, this is the Number One issue in--or rather for--America, as sketched by Ezra Klein:
Sociologists like Juan Linz note that there are very few political systems like ours, because having competing parties installed in competing parts of government that are all able to wield power and claim democratic legitimacy at the same time has historically been a recipe for instability and, eventually, disaster. America has evaded that fate thus far, but now that our parties look more like parties in other parts of the world, the question is whether we can evade it forever. A House divided against itself will eventually fail to raise the debt ceiling, or do something else really dumb.
I suppose Klein is able to assert that "we've evaded that fate thus far" largely because the sectional crisis of the 1850s led to outright disunion, which was an abrupt diversion from the impending, total and irreversible collapse of the American political system. The "debate" shifted from politics to the battlefield, after which the two sections returned, essentially, and regrettably, to a status quo ante. The North continued its industrial progress, the South nestled deeper in racism, xenophobia, and ignorance.
But at least Lincoln Republicans and secessionist Democrats knew what they were fighting over. Today, no particular issue seems at stake. Modern Republicans simply insist on power--all of it. Whatever Democrats want, Republicans oppose it--the concept of an ideological Republicanism is fading. It's not for nothing they're known as the Party of No, as in all-in nihilism. And it's as dangerous and treasonous as antebellum secessionism: it's either their way, or they'll bring this nation to its knees. In a manner it's eerier than secessionism; they merely demand to "govern" as recklessly as they wish. Like all petty tyrants, they'll brook no interference.
Worse yet, Republicans are cornered as well as doomed. They know it. They're slim, singular hope is utter destruction--a calamity so great it'll reset the political equation.
Thus from Klein's reasonable observation, "A House divided against itself will eventually fail to raise the debt ceiling, or do something else really dumb," one is led to ask: What could be dumber, which is to say, more calamitous, than failure to raise the debt ceiling? It's a nihilist's dream.