The Dallas protesters, almost all white men, included bearded outdoorsmen and buttoned-down libertarians. Some said they hid their T-shirts while entering the conventional hall for fear that NRA security would ban them.
Kraut, 31, who says he grew up in a house without guns but as an adult taught his father how to shoot, practices firearms law in suburban Philadelphia and also hosts a video blog called The Legal Brief on The Gun Collective, a YouTube channel.
He has campaigned for the NRA to push for even more expansive gun-rights laws. He wants to change NRA bylaws, such as imposing term limits for board members and mandatory meeting attendance, to renew its leadership.
"Some members feel it (the NRA) doesn't go far enough to defend what we believe to be the core of the Second Amendment," Kraut told Reuters.
One of Kraut's most prominent supporters, Tim Harmsen, who led the pro-Kraut march through the convention center, has 770,000 subscribers to the Military Arms Channel on YouTube, where he criticizes the NRA for being weak on gun laws.
"We're going to continue to apply pressure (on the NRA) every way that we can through social media and we'll be there again next year," Harmsen said.
These hardliners deeply cherish their right under the U.S. Constitution's Second Amendment to keep and bear arms. They oppose any form of gun control, saying criminals will find ways around gun laws, which only strip lawful gun owners of the right to self-defense and protection against state tyranny.
After a shooter killed 58 people at a country music concert in Las Vegas last year, the NRA supported federal regulation of bump stocks, accessories that the gunman used to fire his semiautomatic rifles more quickly. The Justice Department then ordered an effective ban that is close to being finalized.
Amid nationwide protests that followed a Florida high school shooting that killed 17 people in February, the NRA endorsed strengthening background checks for gun purchasers and emergency protection orders that allow law-enforcement officials to temporarily take guns away from people deemed dangerous.
"For us, some of the things that come out of NRA headquarters are just outrageous and abhorrent," said Jeff Knox, a Kraut supporter whose father, Neal Knox, led the "Revolt at Cincinnati" in 1977. "It's: Holy cow, what are these guys thinking?"