As Sarah Brady appears Tuesday at the National Press Club to mark the upcoming 20th anniversary of the gun background check law that bears her husband's name, the Brady Campaign to End Gun Violence is urging Congress to "finish the job" by expanding background checks to apply to all gun sales.

In a one-minute cartoon style ad, narrated in a lisping, child-like voice, the Brady Campaign — which Sarah Brady chairs — asks whether Congress' refusal to extend background checks is a sign that lawmakers are "rooting for the bad guys." Last spring, the Senate voted down a bill to expand background checks for gun purchasers, legislation supported by the Obama administration in the aftermath of the December killing of 20 children and six adults by a gunman at Sandy Hook Elementary School. See the vote here on Open Congress.

The Brady Handgun Violence Prevention Act, which then-President Bill Clinton signed into law on Nov. 30, 1993, represents the last major federal legislative victory for gun control forces that's still on the books. It was named for Jim Brady, a former White House press secretary who was left with permanently debilitating injuries after he was shot in the 1981 assassination attempt on his boss, former President Ronald Reagan.  The law requires background checks of individuals buying firearms. But there are ways around it, primarily by buying guns from a private seller.

Brady Campaign spokeswoman Jen Fuson said the "bad guy" ad was produced for online viewing. She added that another 30-second spot is planned but did not say whether there are plans to air the ad on television stations. 

Recently, the Brady Campaign has not been a major spender on political ads. This is in contrast to two newer gun control groups–Mayors Against Illegal Guns and Americans for Responsible Solutions–which have been airing ads on television stations in markets around the country with competitive races, from California to Colorado to Virginia, according to Sunlight's Political Ad Sleuth tracker. Americans for Responsible Solutions operates both a super PAC and a traditional PAC, while Mayors Against Illegal Guns, is a nonprofit.  New York Mayor Michael Bloomberg, a founder of Mayors Against Illegal Guns, also weighs in on the gun issue through his personal super PAC, Independence USA.

The Brady Campaign's overall political spending has always been low compared to its rival in the National Rifle Association, as Sunlight has reported. Indeed, the Brady Campaign PAC's spending on federal campaigns has fallen abruptly since the year 2000, when it peaked at $1.6 million. Of that amount–75 percent– went toward independent expenditures in several Senate campaigns, according to the Center for Responsive Politics. That presidential election year, Congress had stalled on legislation to strengthen gun control laws following the 1999 shootings at Columbine High School in suburban Colorado, where students Eric Harris and Dylan Klebold shot and killed 12 students and a teacher.

The group's most recent PAC report shows just $2,294 cash on hand, according to Sunlight's Real Time Federal Campaign Finance tracker. This compares to $10.7 million for the NRA and $4.8 million for Americans for Responsible Solutions, the group founded this year by former Rep. Gabrielle Giffords, D-Ariz., and her husband, former astronaut Mark Kelly.

But it is the Brady campaign that can claim the biggest victory. The group's roots stretch back to the 1970s, when it was known by a different name–Handgun Control Inc. Sarah Brady became the group's chair in 1989 and the board of trustees voted to rename the organization in 2002.

The Brady Campaign won important victories during the Clinton administration: In addition to the Brady bill, Clinton signed a ban on certain assault weapons on Sept. 13, 1994. However, Congress let that ban expire ten years later in the face of conventional political wisdom that that vote in favor of the ban had cost numerous Democrats their seats. Despite numerous new gun-related tragedies, however, passage of further comprehensive federal reforms have remained elusive. However, at the state level, over the past year, advocates on both sides of the issue have been eager to claim victory in state and federal races, although results are mixed.