With numbers like those it’s not a surprise that Congress has a hard time finding common ground on much of anything. The changes in the two parties over the last 20 years — ideological and geographic — have simply pushed them farther apart, literally.
Does this mean Congress is stuck in a loop of endlessly growing partisanship? Maybe not.
After years of stasis, the Democratic and Republican coalitions look like they are fragmenting. The Donald Trump’s candidacy and presidency have shaken the traditional fault lines of the American political scene and accelerated what many analysts see as a coming realignment. (Note the Republican struggles to reform health care even with majorities in both houses of congress and the White House.
But for now the two major brands of American politics, the Democrats and Republicans, have formed into tight ideological groups and walked themselves into their respective corners. Without a major shakeup, coming to the middle won’t be easy.