"I have always thought that a big reason why the NRA and gun lobbyists are so powerful is because people are actually scared of them in a very direct and primal way."

This is pretty naive. The gun lobby is successful because it can and will heavily finance opposition to any candidate in any race who opposes NRA goals. Unless your job is absolutely safe, you are forced to pay attention at the peril of losing both your career and livelihood.

Second, feelings about guns touch on one of the deepest divisions in our society, which (roughly) pits city dwellers against people who don't live in cities. The structure of US representative government still greatly magnifies the voices of those who live outside cities, and that culture (for good reason) sees itself besieged by the ascendant beliefs and values of know-it-all, namby-pamby city dwellers.

Each side sees the other as stupid, naive, heavy-handed and ultimately dangerous, which magnifies every policy dispute into an emotional, almost existential battle.