The national debate over gun control took center stage at the US Senate last week when Senator Chris Murphy, D-CT, and allies staged a 15-hour filibuster to force action on gun control legislation. The talk-a-thon ended only when the Senate agreed to hold votes on legislation banning gun sales to individuals on the government’s terrorist watch list and on expanding background checks.

The filibuster came three days after the mass shooting (49 dead) at Orlando, FL’s Pulse nightclub, 1,280 days after the massacre (27 dead) at Sandy Hook Elementary School in Connecticut, 3,339 days after the Virginia Tech murders (32 dead) and 6,267 days after the tragic shooting (13 dead) at Columbine High School in Colorado.

This stunning record of congressional inaction is largely the handiwork of the National Rifle Association. The NRA is one of the nation’s biggest campaign contributors. Common Cause estimated last year that the NRA spent at least $31.4 million on the 2014 midterm elections alone– spending mostly accomplished through independent political groups, not directly to candidates. In addition to this electoral spending, the NRA has spent over $35 million on lobbying against both campaign finance reform and gun control laws since 1998.

The NRA’s power highlights the dangers of big money’s political influence. Even before the Orlando shooting, a CNN/ORC poll showed that 67 percent of Americans — including 51 percent of Republicans — support expansive gun control initiatives announced earlier this year by President Obama. Other polls put support of mandatory background checks for gun ownership at over 90 percent.

Yet, in 2013, bills mandating background checks and banning assault weapons failed. The failures suggest representatives are more attuned to the interests of their NRA funders than those of their constituents. To see where your congressman stands on money in politics, visit whowillfightbigmoney.org. A list of the top 20 congressmen backed by the NRA, and their phone numbers, can be found here.