It’s safe to say that we can all remember where we happened to be on this day 13 years ago. For my part, I was in a non-descript hotel room in a non-descript corporate park in Thousand Oaks, California. I had flown to LAX the day before to meet with a client in the bio-tech industry. I got up very early that morning to do a conference call with two merchant energy traders based in Atlanta. I was hoping they would become my next clients. About halfway through the call, the trading floor they had dialed in from was taken over, first by pagers going off, then frantic shouts. They just said, “The floor is going nuts, we gotta go,” and hung up. Not quite sure what had happened, I clicked on the TV to find out, and so I saw the scenes that horrified and transfixed us all that September morning.

The violence of that day pushed my normal preoccupations with client work and commercial prospects into the background. I experienced, along with many others, unprecedented feelings of solidarity with my fellow citizens and a corresponding sense of patriotism. I received the kindness of strangers and sought in turn to share it with others. For all of the death and loss that 9/11 rained down, it felt like we were living in a different country, one that had painfully rediscovered some misplaced but vital truths.

The surge of connection and affiliation that we felt in the wake of 9/11 was mirrored in a sudden and dramatic increase in approval of Congress. As this Gallup chart shows, from 1974 through 1997, approval ratings for Congress fluctuated, but consistently stayed in the 20-40% range. Beginning in 1998, approval ratings had begun edging up and were oscillating between the low forties and high fifties. A poll conducted by Gallup days before the attack found that 42% of Americans approved of “the way Congress is doing its job.” One month after 9/11, Gallup found that Congress’s approval rating had doubled, to 84%.

In many respects this upsurge is not surprising. Americans were rallying around their government and its institutions in the aftermath of the attack by Al Qaeda. A Gallup survey tracking public trust in government also showed a sudden increase, peaking at 60% in October 2011.

Perhaps the sharp spike in the public’s approval of Congress was due in part to the fact that the divisiveness, partisanship, and frustration that tend to emanate from the institution faded into the background for a time, enabling many of us to appreciate anew the ideas and values that the institution was meant to embody. These ideas and values were suddenly under assault—literally so with the subsequent discovery of Anthrax-laden letters in the congressional mailroom. It was natural to approve of and thus affirm what Congress stood for in that moment.

But the chart also shows that, just as our newly felt social solidarity faded as the months stretched on after the attacks, so did congressional approval ratings. Within a year they had returned to pre-9/11 levels, and—with the exception of a brief uptick in the early days of the first Obama Administration—they have declined steadily ever since. For the last three years, less than one in five Americans have approved of Congress. At the height of last year’s government shut down, not even one in ten did.

The secular downward slope to the recent nadir raises questions about what will happen when future attacks or emergencies hit the country—as they surely will—in ways that put the resilience of representative democracy to the test. Will we be able to rally around our system of government in general and Congress in particular from such a low baseline of support? Will we be able to respond effectively as a nation if we cannot? Will Congress be able to act, and if it does will its actions have sufficient legitimacy? These are questions we should consider on this day, and in the days that lie ahead.