As the debate over gun regulation intensifies, the National Rifle Association’s role in the public dialogue and its influence on Congress has sparked national interest. While the NRA is a private organization, it has been classified by Open Secrets as a “Heavy Hitter,” or one of the 140 biggest overall donors to federal elections since the 1990 election cycle.

In 2012 alone, 271 candidates received donations from the NRA, totaling $700,000. As reported by USA Today:

“The NRA has had great influence because they have largely had the field to themselves,” said Robert Spitzer, a political scientist at the State University of New York College-Cortland and author of The Politics of Gun Control.

The NRA has spent ten times more to lobby Congress than pro-regulation groups, a factor that is largely accredited to their influence over the political dialogue of gun policy.

NRA spokesman Andrew Arunanandam disputes the association between lobbying and policy, citing American attitudes against stricter gun control as a leading factor in the NRA’s success. “Successes are due to the fact that the overwhelming majority of American people agree with our position, not because of any influence,” he says.

A revealing Pew Research Poll, however, shows that public opinion on gun policy in shifting. Released yesterday, Pew reports that 85% of Americans favor background checks for private and gun show sales and 55%favor a ban on assault style weapons, two key issues on Obama’s agenda in reforming gun policy.

In an effort to visualize the NRA’s influence on Congress, the Washington Post has created a series of graphics, which we’ve posted below:

NRA influence Congress How Much Does The NRA Influence Congress?SOURCE: Center for Responsive Politics, Sunlight Foundation, Project Vote Smart, NRA. GRAPHIC: Wilson Andrews, Dan Keating and Karen Yourish – The Washington Post. Published Jan. 15, 2013.