If you’ve been paying even casual attention to American politics recently, you can’t be surprised that gun-control legislation died in the United States Senate Wednesday. But even for those of us cynical about the prospects for Washington to act in any meaningful way, the day’s votes were a stark reminder of how anti-democratic and dysfunctional our political architecture is.

Who would design a system in which a President recently reëlected by a margin of almost five million votes could not move a piece of legislation supported by some ninety per cent of the country through even one chamber of the Congress—even when a majority of legislators in that chamber voted for it?

Almost every defect of our creaking political system was on display.

1. The Filibuster

Imagine that you were one of the family members of a victim of Aurora or Newtown sitting in the Senate gallery Wednesday. You would have watched as three gun-control measures were brought to the floor and easily secured the support of more than fifty senators: the main background-check bill (fifty-four votes), a mental-health bill (fifty-two votes), and a gun-trafficking bill (fifty-eight votes). But none of the bills passed because the Senate now operates as an institution requiring a supermajority of sixty votes for any legislation to move. Try explaining that to a mother whose child was gunned down in a first-grade classroom in Connecticut.

2. The Tyranny of Small States

Even without the filibuster, an extra-Constitutional and arbitrary Senate rule, the upper body is structurally designed to give enormous weight to tiny populations of Americans at the expense of everyone else. The two senators from California, who voted for background checks, represent thirty-eight million Americans, or twelve per cent of the population. The two senators from Wyoming, who voted against the measure, represent five hundred and seventy-six thousand Americans, or less than two-tenths of a per cent of the population.

To get a sense of how this anti-democratic differential has exploded over time, just look at this chart of the population growth of Wyoming and California:

As Alec MacGillis nicely outlines, the ratio of the largest American state to the smallest American state has jumped from eleven to one to sixty-six to one since the Senate was created.

3. Asymmetric Polarization

Perhaps the most important feature of contemporary American politics is the way the two parties have completely sorted the electorate and moved closer to the extremes. That is, all liberals are now in the Democratic Party, which has moved left, and all conservatives are now in the Republican Party, which has moved right. (You can see what it looks like on a graph.) But crucially, the Republican Party is more ideologically homogenous and has moved farther to the right than Democrats have moved to the left, a phenomenon that’s captured nicely in another graph:

In this environment, G.O.P. senators generally worry more about primary challenges from more right-wing Republicans than they do about general election battles from Democrats. And it means that on issues like gun control, many Senate Republicans in safe red states are wildly out of step with national opinion on issues like background checks but believe they will suffer no electoral consequences.

4. Our Weak Presidency

Facing a Congress in which the House is controlled by Republicans and the Senate is hobbled by the filibuster, Barack Obama’s legislative strategy this year leans heavily on his use of the bully pulpit to shame Republicans into backing his initiatives, especially on gun control. But even on an issue with overwhelming public support, Obama’s poignant speeches, numerous campaign-style events, and the use of his new political arm (Organizing for Action) were no match for the N.R.A. It’s even possible that his campaigning hardened opposition to the proposals and bolstered the N.R.A.’s efforts. (I spent some time shooting shotguns and an AK-47 with three gun enthusiasts in Arizona recently, and they all viewed Obama’s current gun-control agenda in near-apocalyptic terms.)

Obama’s answer on that was angry: “I’ve heard folks say that having the families of victims lobby for this legislation was somehow misplaced. ‘A prop,’ somebody called them. ‘Emotional blackmail,’ some outlet said. Are they serious? Do we really think that thousands of families whose lives have been shattered by gun violence don’t have a right to weigh in on this issue? Do we think their emotions, their loss is not relevant to this debate?” Maybe not, but it wasn’t enough to win.

So what does the defeat of gun control mean going forward? It’s hard to say. (My colleague John Cassidy argues that the N.R.A. may have at last overreached.) Trying to reduce violence from firearms is an idiosyncratic issue in which the intensity is all on the side of the opponents, so we can’t necessarily draw too many lessons for other issues working their way through Congress. And indeed there are some encouraging signs for other parts of Obama’s agenda, especially immigration. But Wednesday’s action in the Senate is a reminder that it’s prudent to be skeptical that Congress will pass anything important this year.

Photograph, of President Obama speaking about gun control in the Rose Garden, by Mandel Ngan/AFP/Getty.