The Washington gun-control debate in which President Obama and fellow Democrats are trying to promptly tighten firearms laws is emerging as a longer effort with both sides spending millions on congressional candidates who will help or hurt their cause.

The National Rifle Association spending on new ads this week was no surprise, considering the powerful and well-funded gun lobby spent roughly $18 million through its political arms in the last election cycle. And the group remains committed to protecting gun makers and the Second Amendment rights of gun owners.

However, the emergence of New York Mayor Michael Bloomberg and his super PAC spending roughly $2 million this year on a special House race in Illinois suggests both sides are looking to bolster their positions in Congress through the 2014 races and perhaps beyond.

Bloomberg, a vocal advocate of strict gun control, through his super PAC Independence USA, paid for TV ads and mailers attacking two Illinois Democrats -- former Rep. Debbie Halvorson and state Sen. Toi Hutchinson -- who were running for Jessie Jackson Jr.’s open seat and have had high NRA ratings. The primary is Tuesday and considered too close to call.

Halvorson doesn't support a ban and has accused Bloomberg of trying to "buy an election."

Hutchinson, the early leader, has quit the race and put her support behind fellow Democrat and former state Rep. Robin Kelly, who like President Obama and other Washington Democrats supports an assault-weapons ban.

Their efforts follow a series of mass shootings including the Dec. 14, 2012, incident in Newtown, Conn., in which 20 first-graders and six adults were killed.

Two days later, Obama ordered a task force to come up with a set of proposals no later than January and called for “real reform right now.”

Independence PAC spokesman Stefan Friedman pointed out that Bloomberg has spent money in previous races in which his topics of concern have been involved and suggested the mayor would continue with such efforts.

“The mayor has been clear, no matter where it may be, with issues like gun safety and the environment, he’s going to be there to educate voters,” Friedman told FoxNews.com. “The mayor’s never been shy about spending what it takes.”

He disagreed with the notion that backers of tighter gun laws are looking at future elections because they do not expect this Congress to pass bans on assault weapons and high-capacity gun magazines. Friedman said the country “fully supports” Obama’s reform package, which he expects to “pass immediately.”

This week, the NRA ran full-page newspaper ads primarily targeting three Senate Democrats up for election in Republican-leaning states: Sens. Mark Pryor, Arkansas; Mary Landrieu, Louisiana; and Kay Hagan, North Carolina.

The group also purportedly ran in ad in West Virginia where Democrats hope to retain the seat of retiring Sen. Jay Rockefeller and in at least 10 swing states.

The NRA could not be reached for comment, but group Executive Vice President Wayne LaPierre has argued the president had gun control as a second-term agenda before the Connecticut shootings.

“It's not about keeping our kids safe at school,” he said after the president’s State on the Union speech this month. “That wasn't even mentioned in the president's speech. They only care about their decades-old gun control agenda

Bloomberg launched his super PAC weeks before the November election and spent more than $12 million to back seven candidates nationwide. Guns were an issue in the election of newly-elected Rep. Gloria Negrete McLeod, a California Democrat who ousted incumbent Democrat Rep. Joe Baca with Bloomberg's help.

However, Bloomberg's backing hasn't always equaled success. His super PAC supported former Rep. Robert Dold, R-Ill., who lost to a Democratic businessman, Rep. Brad Schneider.

Ben Tulchin, president of the San Francisco-based polling firm Tulchin Research, argues Bloomberg has been very strategic about where he spends such money and that he perhaps single-handedly changed the Illinois race.

“Without Bloomberg’s money, it would have been almost impossible to have what happened,” he said Wednesday. “He basically flipped that seat. … The two Democrats fell, but it was Bloomberg who knocked down the first domino.”

The Associated Press contributed to this report.