CHICAGO: An outspoken gun control supporter is poised to take a seat in the U.S. Congress, and her win is seen as a victory as well for the organization founded by New York City's billionaire mayor to counter the country's powerful pro-gun lobby.

Democratic nominee Robin Kelly directly challenged the National Rifle Association in her victory speech Tuesday night. Her Chicago-area district is overwhelmingly Democratic, and she is expected to sail through the April 9 general election and head to Washington.

The gun issue has returned to the national spotlight after 20 young children and six adults were killed in a school shooting in December by a man using his mother's legally purchased high-powered rifle.

Vice President Joe Biden, who has led White House efforts on gun safety, said Wednesday that voters in Kelly's win "sent a clear, unequivocal signal" to the NRA and politicians nationwide. "The message is there will be a moral price as well as a political price for inaction."

Kelly, who would replace disgraced former U.S. Rep. Jesse Jackson Jr., gained huge momentum as New York City Mayor Michael Bloomberg's political action committee poured $2 million into anti-gun television ads in her favor. They blasted one of her Democratic opponents, former U.S. Rep. Debbie Halvorson, for receiving a previous high rating from the NRA. Kelly supports an assault weapons ban. Halvorson does not.

"We were on the right side of the issue, and our message resonated," Kelly told The Associated Press shortly after her win.

Kelly promised in her victory speech to fight "until gun violence is no longer a nightly feature on the evening news" and directly addressed the NRA, saying "their days of holding our country hostage are coming to an end."

Bloomberg called Kelly's win an important victory for "common sense leadership" on gun violence, saying in a statement that voters nationwide are demanding change from their leaders.

But other Democratic front-runners accused Bloomberg of buying a race and interfering in the heavily urban district.

"It shows, unfortunately, you can't go up against that big money," Halvorson told the AP.

Political experts and fellow candidates said the committee's money made all the difference, particularly in an election with a short primary and low voter turnout.

"The money bought Kelly a tremendous among of attention," said Laura Washington, a political analyst in Chicago. "She tapped into a real hard nerve out there in the community. People are really concerned about gun control and violence. She was smart to focus like a laser on that issue."

Bloomberg, a Democrat-turned-Republican-turned-independent, has long taken a vocal stance against guns. He launched his committee weeks before the November election and spent more than $12 million to back seven candidates nationwide.

However, gun rights advocates dismissed the notion that Kelly's election and Bloomberg's attention would fuel the national debate on gun control.

"This is an aberration," said Illinois State Rifle Association spokesman Richard Pearson. "This shows what you can do with $2 million in an offseason race. He bought the election is the way."