Congressional partisanship is increasingly dividing lawmakers, policy debate is split along party lines, and the dissenting voice is diminishing in American politics.

The cause? The increasing tendency of lawmakers to vote along party lines, making the debate over issues one-dimensional. The moderate voice in Congress has all but disappeared, and between the years 1965-2004, the dissenting voice has been muted.

Ashley Joachim and Bryan Jones further explain,

Issue-centric conceptions of congressional voting were replaced by ideological ones emphasizing the power of party and ideology to readily simplify the complexities of congressional life.

The Washington Post's Ezra Klein shows us why Congress is increasingly polarized, dissent is low, and debate is one-dimensional, in one chart:

Frustrated? So are most Americans, and Congressional approval ratings are at an all-time low. Join us Thursday, August 9 to discuss real solutions with non-partisan group No Labels on Twitter. Want more information about our tweet chat? Click here.