There are lots of ways in which members of Congress differ from the American people. They are wealthier, whiter and older. Proportionally more of them are men, and far more are lawyers. All of these differences can affect congressional deliberations, but none matches another yawning gap that has opened up between Congress and average Americans: Congress, unlike the country at large, is noxiously partisan.

Yes, there are partisan divisions among voters. But most Americans want to see our challenges addressed pragmatically. They are not especially interested in ideologically driven legislative maneuvering, and have almost no patience for political leaders who zealously seek partisan advantage. They want politicians to find common ground — not dwell on their differences, promote special interests or place party loyalty ahead of national progress. Americans see the value in compromise, accommodation, and civility.

Congress, on the other hand, is filled with people who barely talk to each other, do their best to undermine the other side, and seek partisan advantage at every turn. There are exceptions, but I’m always struck by news stories outlining efforts to bridge the partisan divide — that these are news, rather than commonplace occurrences, highlights the problem.

How did Congress get to the point where partisan polarization has become the most prominent feature of American politics? There’s no single reason.

The gerrymandering of congressional districts certainly has hurt. More often than not, people running for Congress do so in districts drawn to favor one party or another. This means that if there’s a political threat, it’s from members of their own party. There is very little reason for a candidate to consider the views of people across the political spectrum or to move to the center. Instead, the candidate must focus on the small number of partisan activists who dominate primaries.

As New York Mayor Michael Bloomberg points out, good transportation hasn’t helped either. Instead of going to restaurants together or going to their kids’ birthday parties, members of Congress leave Washington on Thursday and spend as much time as possible in their districts. They have few opportunities to get to know one another.

The partisan divide is also exacerbated by changes in the media. The 24-hour news cycle and instant analysis have forced politicians to take positions before they really have time to think them out. Social media, for its part, creates a referendum virtually instantly on every issue. Politicians need time to study and ponder issues; instead, it’s as if they face an election every day on every issue before them.

The result is that the sheer intensity of our politics has been ramped up — with money, lobbyists, interest groups, reporters, bloggers, and countless ordinary-citizen commentators adding to the pressure politicians feel, raising the stakes and amplifying the feelings on every issue.

Just as there’s no single cause for Washington’s out-of-control partisanship, there’s no single solution. We need to find ways of reducing the outsized role of money in politics, eliminating the partisan gerrymandering of districts and opening up state primaries, so that interest groups and partisan activists have a harder time dominating elections. Congressional leaders need to expand opportunities for members to get to know one another and their families, principally by paying attention to the work schedule; it’s hard to get mad at someone you know well, much less demonize him or her.

But perhaps the most important effort would be to expand the electorate. Low turnout in our elections greatly enhances the power of highly partisan voters. More voters would force politicians to listen to a wider range of views. It would tilt the balance toward where most Americans are — somewhere around the middle.

Too often, “debate” these days is just the two parties’ talking points hammering at each other in a mean-spirited, strident tone — not a genuine dialogue that searches for common ground and a solution to the problem. Changing this will require you and me to make it clear to our political friends that we do not like divisive name-calling, constantly attacking an opponent’s motivation or blatant partisan calculation. Let them know that we all pay the price for excessive partisanship, and we’re tired of it.