We sometimes don’t notice history as it’s unfolding right before us, so let’s stop and take note of what a historically momentous day Tuesday was. Twenty, 50 years from now, when historians or college professors are trying to describe to their readers and students what the difference was between the two political parties in our time, they will direct them to October 1, 2013. That one day says it all.

The Democratic Party was opening up its historic program to bring health care to all citizens, and the Republican Party was closing down the federal government, a fanatical minority manipulating the rules of our democracy and holding a gun to the country’s head, all because it wants to deny all citizens health care and is furious that it failed three times in that effort.

Tuesday perfectly expressed what these two parties have come to be about. The Democrats have many flaws, and money has corrupted them at certain times on certain issues almost as much as it has corrupted Republicans. And yes, sometimes some Democrats behave divisively, too. But at least they have had good moments, even great ones. The passage of Social Security. Medicare and Medicaid. Civil rights (and please, you cynical Everett Dirksen-invokers, give it a rest and go away; you would have long since drummed Dirksen out of your party today). Women’s rights. And most recently gay rights, including same-sex marriage; history will recall Barack Obama with admiration as the first sitting president willing to voice his support for that.

This is where you might expect me to say the evil Republicans were implacably opposed to every one of these great advances at every turn. But that isn’t the case. In 1935, majorities of Republicans backed Social Security—not by anywhere near the percentages Democrats did, but they supported it. Thirty years later, about half of Republicans in both houses of Congress backed Medicare and Medicaid. And yes, Dirksen and other Republicans were important allies for Lyndon Johnson on civil rights against the racist and reactionary Southern wing of his own party.

The GOP was wagging the tail of the dog of history in those days—while it wasn’t leading the fights, a respectable number of Republicans signed onto them. Still, wagging a tail is a far sight better than cutting one off with a rusty serrated knife. And that’s all the party of resentment does these days.

Universal health care has been discussed in the United States for a century. It never succeeded before because of the powerful business and vested interests that opposed it. In Harry Truman’s day, the American Medical Association assessed its members an extra $25 in dues to fight Truman’s universal health care plan, and the AMA won.

This time, opposition to universal health care isn’t chiefly financial. The AMA even endorsed Obamacare. It’s chiefly cultural, right-wing rage that Mitt Romney’s 47 percenters are getting something for nothing (which they aren’t, of course). Read the comments of some of the Tea Party House Republicans who are delighting in the shutdown, absolutely convinced they’re doing the right thing. “What was I elected for? To try to change the law on behalf of my constituents, to stand on my core principles and do my best to represent them ethically, honestly, based on the core principles we share,” Rep. John Culberson (R-TX) told the Times.

I believe him. He and the others aren’t doing this because some fat cat lobbyist is lining their pockets. They’re doing it because it’s a matter of those “core principles” they share. But what are the principles? Not faith in the free market—Obamacare is a free-market program (ask the insurance companies!). Not concern about spending—there are early, tentative signs that Obamacare is contributing to a reduction in overall health care spending. Don’t take it from me, take it from Forbes.

Culberson and his constituents of course wouldn’t put it this way, but I think the principles look a lot more like toxic hatred of government; belief that health care has to be “earned”; conviction that Obama and the Democrats want to create a society of freeloaders; fear that one way or another, it’s all going to come out of their hides.

This is what this feral opposition is about. It’s certainly not because Republicans and conservatives have specific criticisms of Obamacare and better ideas they want to implement. You will have noticed that the Republican Party has long since stopped bothering to pretend to have any health-care ideas of its own. How long has it been since you heard “repeal and replace”? They dropped that “replace” ages ago. They dropped it because it was a pretense the whole time. They have zero ideas about how to insure the uninsured. That’s because they don’t give a fig if the uninsured become insured. They’ve got theirs, and they want to be left alone.

Every society is locked in a battle between two visions. One says we have some degree of collective responsibility to each other; that you “earn” the “right” to something like health care not when you’re lucky enough to land a good, non-Walmart job but the day you are born; and that we’re all better off when...well, as my friends Nick Hanauer and Eric Liu say, when we’re all better off.

And there are those who have a vision, if one can call it that, that sees all the above as not just unfortunate but iniquitous. And today, in the age of Obama, sent over some psychic edge by the ascendance of a black president, their collective rage is transmitted to (and shared by) their representatives, who then believe that any means of resistance is justified.

It’s these two visions we saw manifested Tuesday, as some 3 million Americans tried to sign up for health coverage while the Republicans and their pathetic speaker peacocked around the Capitol trying to stop history. But you can’t do that, and there is no question years from now which vision history will judge more kindly.