CHART OF THE DAY…. If it seems as if the major parties in Washington are further apart ideologically than at any point in our lifetimes, that’s because they are.

I suspect most political observers would have guessed this intuitively, but it’s helpful to have the results quantified, taking this out of the realm of supposition. Jonathan Bernstein flagged this chart, published by political scientist Keith Poole, plotting “the level of polarization between the two parties in Congress from the 46th Congress (1879-1880) to the most recently adjourned 111th Congress (2009-2010).” (Click on the chart for a larger view)

The parties in the House were the most polarized ever during the Bush/Cheney era, and they’ve grown progressively more polarized in each of the last four Congresses, reaching yet another new high last year.

The Senate isn’t quite at a record level, at least not yet, but the chamber is meeting polarization levels unseen since the 1870s — when the country was still dealing with the aftermath of the Civil War.

Polarization rates reached their ebb in the 1940s, when Republicans effectively moved to the center and the New Deal established a new national norm. Those days, obviously, are a distant memory.

I suspect there will be some on the right who look at a chart like this and insist the growing chasm between the parties is the result of radically-liberal Democrats. Not only is that silly on its face, it’s also disproven by the data. As Ezra Klein noted, “A bit later in the piece, [Poole] breaks the numbers down further and finds that the high level of polarization was primarily a result of Republicans being more polarized than ever before. Democrats … were pretty well within their historical norms.”

For a D.C. establishment preoccupied with centrism and bipartisan cooperation, here’s hoping folks realize which side of the aisle is responsible for partisan divisions.

I should emphasize, though, that this isn’t necessarily criticism. The parties are supposed to disagree, and there’s nothing wrong with Democrats and Republicans fighting for very different principles and agendas. In some respects, it’s helpful to voters to have sharp distinctions between the parties, better clarifying the directions available to the country, and ideally making the electorate’s choices easier.

The problem, of course, is that the system wasn’t designed to work well with this level of polarization. The policymaking process is supposed to be cooperative, and that’s a tall order when the parties are so far apart, they can barely see one another.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.