A little known pro-gun lobby that’s well to the right of the National Rifle Association has complicated efforts to reach a solution on gun control legislation, top Democrats have said in recent days.

The Gun Owners of America has been around for decades, operating mostly in obscurity, dwarfed by the lobbying and fundraising prowess of the NRA. The group’s big gripe is that the NRA is too squishy and willing to compromise, and its recent efforts to scuttle gun control legislation appear to be scaring away Republicans amenable to background checks.

The results have frustrated Democrats trying to strike a bipartisan deal.

“The NRA — their lobbying efforts are being pushed even further to the extreme by virtue of the fact that there’s another organization called Gun Owners of America,” Senate Majority Leader Harry Reid (D-NV) told Nevada Public Radio on Friday. “Whenever the NRA tries to be reasonable, the Gun Owners of America becomes more unreasonable, and it pushes the NRA [to the right].”

GOA is proud of its obstinacy against gun control. In a New York Times profile of the group last week, its executive director Larry Pratt took credit for scaring away Sen. Tom Coburn (R-OK) from discussions with Sen. Chuck Schumer (D-NY) about a bipartisan compromise on expanding background checks for gun purchases.

“His staff admitted that it kind of irritated the senator,” Pratt told the paper. “We were told, ‘He’s getting tired of this.’ But when we hear complaints like that, we know we are close to success. We are happy he changed his mind.” He said GOA mobilized its proclaimed 300,000 pro-gun members to inundate GOP lawmakers with phone calls.

Schumer’s spokesman Brian Fallon took note of Gun Owners of America’s role in the debate, tweeting a link to the Times profile and saying the group “is making deal on even background checks extremely hard.”

Less clear is the extent to which Gun Owners of America is the true foe of expanded background checks, rather than a scapegoat for Senate Democrats who are facing potentially tough reelection battles in red states and are skittish about supporting any significant new gun restrictions. For now, negotiations over background checks continue, as Democrats are now seeking to win over Sen. Pat Toomey’s (R-PA) support for a compromise deal.

Meanwhile, the Gun Owners of America is flexing its muscle in first major gun control effort in nearly two decades. Prominently featured on the front page of GOA’s website is a quote from Ron Paul calling the group “the only no-compromise gun lobby in Washington.”