The problems with the current Senate rules — namely the abuse of the filibuster by Republicans — are well known. Less well understood is how the Senate by designempowers the residents of small states at the expense of residents of larger states. This fact explains why a policy like background checks that enjoys the support of over 90 percent of Americans can still be killed in the Senate through a combination of filibuster abuse and the Senate’s bias toward small states.

ThinkProgress’ Ian Millhiser explains how this worked in the case of last night’s shameful Senate vote against expanded background checks: