By Renita Young
CHICAGO, Feb 21 (Reuters) - New York Mayor Michael Bloomberg's push for stricter U.S. gun laws in the wake of the Connecticut school massacre faces a stern test next week in a messy Chicago special election where he has piled in with more than $2 million in political ads.
The outcome of the race is the first big election test since the Newtown, Connecticut, shooting of whether gun control champions such as Bloomberg and former U.S. congresswoman Gabby Giffords can use money, and the same tough tactics as gun rights lobbyists, to influence voters.
Gun control vaulted to the top of the U.S. political agenda after a gunman last December shot and killed 26 people at an elementary school in Newtown including 20 children.
Bloomberg is taking a risk by wading into the nasty and racially charged politics of Chicago, where critics have already complained the brash mayor is trying to buy an election nearly 1,000 miles (1,600 km) from New York City.
The Feb. 26 primary is to replace U.S. Congressman Jesse Jackson Jr., who pleaded guilty in federal court on Wednesday to using campaign funds to finance a lavish personal lifestyle.
Jackson was a reliable vote in Congress for gun control measures but polls last month showed the seat could be won by Debbie Halvorson, who has an "A" rating from the powerful gun rights lobby, the National Rifle Association, and opposes an assault weapons ban.
The winner of the Democratic primary is likely to win the seat because the district is heavily Democratic.
Bloomberg's Independence USA political action committee, or PAC, has blanketed Chicago television with more than $2 million in ads attacking Halvorson's stance on guns and endorsing Robin Kelly, a candidate supporting gun control, according to PAC spokesman Stefan Friedman.
"Halvorson would have probably won this district if the gun control issue hadn't intervened," said Dick Simpson, a former Chicago city council member and political scientist at the University of Illinois, Chicago. "Whether she still can win it is unclear."
The district at stake is majority African-American and includes some areas ravaged by gun violence, as Chicago's murder rate reached the highest in five years. The district should be receptive to Bloomberg's message of gun restrictions.
But it also stretches south to the outer suburbs of Chicago where some white voters are in favor of gun ownership.
Halvorson is the only white candidate among the 14 Democrats still vying for the seat. The concern among some in the black community is that the black vote will split, allowing Halvorson to win the primary with only about a third of the vote.
There have been no public polls in weeks and both sides are touting private polls showing they are winning the gun battle.
Halvorson is fighting back, saying Bloomberg misrepresented her position on guns. She said that she supports registration of all firearms and background checks for gun purchases, but opposes a ban on assault weapons.
"(The commercials) are so over the top. They are unbelievable. They also are false, because they say that I am endorsed by the NRA, which I am not," Halvorson said.
The Illinois State Rifle Association, which is aligned with the NRA, said it does endorse Halvorson.
"I think that (Bloomberg) is trying to take advantage of a tragedy," association executive director Richard Pearson said, referring to the Connecticut shooting. "And I think that you hear less talk about victims and it's more about getting his agenda done."
Halvorson and Chicago city council member Anthony Beale, who is also vying for the seat, accused Bloomberg of trying to "buy" an election.
Bloomberg and his allies are unbowed by the criticism.
"The mayor has been clear that when these issues are in play, he believes it's a good use of time and resources to help educate the public about the candidates' position on them," Friedman said. (Reporting by Renita Young; Editing by Greg McCune and Dale Hudson)