How Big Money Created the Most Polarized Congress in a Century: 5 Charts

Every year, the Brookings Institution and the American Enterprise Institute put out the fantastic Vital Statistics on Congress, and this year's edition lands Tuesday. (Atlantic contributor Norm Ornstein co-authored the report with Tom Mann.) You can check out the entire thing here, with more data than you can possibly imagine on subjects you've never considered.

I wanted to pull out four graphs that show a somewhat different angle on Congress -- one of America's most loathed institutions -- than the usual.

That's the cost of a winning campaign on the left axis, all in 2012 dollars. (The campaign cash numbers in Vital Statistics come from the Campaign Finance Institute, whose Michael Malbin is a co-author on the report). No surprise there, right? Nor is it a shock that it costs a lot more to win a Senate seat than a House seat (though of course you can no longer buy one the way William Clark did back in 1899). But what's a little surprising is how consistently (if slowly) the price of a House seat has grown compared to the price needed to win a Senate seat, which has been far more volatile. Anyone know why the price dropped so dramatically in 2002?

Political-action committees are the biggest story of the last two decades in campaign finance, but just how quickly have they grown? The trend from 1978 to 2012 is pretty astounding: PACs gave just $34.1 million to candidates at the start of that span, compared to $425.5 million in 2012. But the PAC data also tells a story about who's gaining and who's losing power in contemporary America. Look at what labor PACs spend back in 1978 -- more than corporate groups, and nearly as much as trade groups. Since then, all three groups have grown, but while unions' share has remained surprisingly flat since 1996 or so, trade groups and especially corporate PACs have far outpaced them:

Time was, Americans might vote for a presidential candidate of one party and a House candidate from another. That's a vestige of a less politically contentious age, but particularly of one with less ideological sorting in Congress: There were plenty of conservative Democrats and liberal Republicans. With those wings gone, look at how precipitously vote-splitting has declined:

There's a reason 1972 and 1984 are such vast outliers: In both cases, a presidential candidate (Richard Nixon and Ronald Reagan, respectively) won by a landslide, as voters overwhelmingly rejected Democratic challengers. But in both cases, that didn't mean local voters were willing to throw out their own Democratic reps. It looks like the trend is returning to something more like the norm a century ago.

Another result of the current political climate is a greater willingness to throw the bums out. In 2012, long-serving senators headed for the exits. Some were thrown out by primary voters (Indiana's Dick Lugar), others by party conventions (Utah's Bob Bennet); some left in the face of likely defeat (Connecticut's Joe Lieberman); and some just decided to retire (Hawaii's Daniel Akaka). The result is a Senate of almost unprecedented youth, with a median length of service exceeding only the 1981 Senate, which was shaken up by the Reagan Revolution.