Bumper stickers hang for sale at the Second Amendment Foundation booth an annual NRA convention. The National Rifle Association spent $24 million this last election cycle. - 

Yesterday, Sen. Diane Feinstein (D-Calif.) said she plans to introduce a bill that would ban assault weapons. A similar ban expired, back in 2004. 

That legislation is sure to attract attention -- and money -- from two special interest groups: the Brady Campaign to Prevent Gun Violence and the National Rifle Association. And if you look at those two groups side-by-side, comparing the resources they have, it will be far from a fair fight.

The NRA is the largest gun lobby, and it’s got a reputation in this town.

“The word in Washington is that crossing the National Rifle Association is dangerous,” says Graham Wilson, who Boston University’s political science department.

It has been known to pour hundreds of thousands of dollars into a single congressional race. According to Lee Drutman, of the Sunlight Foundation, during the last election cycle, the NRA spent more than $24 million. “The money on one side is enormous. The money on the other side is tiny.”

In contrast, Drutman says, the Brady Campaign to Prevent Gun Violence -- the largest gun control organization -- spent just $5,816 during the election. Total.

Neither group responded to our requests for interviews.

The NRA’s cash advantage could serve as a powerful check against any new gun control efforts. According to Sheila Krumholz, who runs the Center for Responsive Politics, the NRA is already gearing up for the 2014 midterm elections.

“The NRA alone has given to more than 290 candidates already this cycle so far,” she says. “So, that’s a lot of money in a lot of pockets in Washington.”

Drutman calls the NRA a “textbook political organization,” because its members make it so effective.  There are more than four million of them, and the NRA’s membership has grown after other mass shootings.

“The NRA gets more members at times when gun control laws are on the table,” he says. “In the wake of Columbine, they increased their membership by about 50 percent.”

When it comes to money and members, there’s not an organization on the other side of the gun control issue that compares. 

Follow David Gura at @davidgura