While Chicago Mayor Rahm Emanuel has publicly remained neutral, his personal and political friend, New York City Mayor Michael Bloomberg, is a major player in the campaign to replace Jesse Jackson, Jr. in the 2nd Congressional District.
However, most of those running in the special election wish that Bloomberg would butt out.
"Why should one person intimidate others who want to run for office? What's next?" said Halvorson.
Halvorson has seen enough. She is outraged by the super PAC negative ads that first targeted her and later the candidacy of Illinois State Senator Toi Hutchinson. Bloomberg's Independence USA PAC reportedly will spend up to $2 million on the Illinois 2nd Congressional District race.
"I mean, a billionaire like Mike Bloomberg -- $2 million or $3 million is a drop in the bucket to him," said Halvorson.
The latest ad endorses Robin Kelly, who denies a Halvorson charge that she has made illegal contact with either Independence USA or with Bloomberg.
"It's ridiculous, that's how I can respond -- don't know him, he doesn't know me," said Kelly.
Hutchinson dropped out of the race Sunday, only days after she was targeted by Bloomberg. At the same time, the state senator endorsed Kelly, who as recently as Saturday sent a negative mailer about Hutchinson.
Alderman Anthony Beale, the only Chicago elected official in the race, is the major candidate not mentioned in negative ads. He is running a ground game aimed at turning out the 40 percent of 2nd Congressional District voters who live in South Side wards.
He predicts the New York City mayor's involvement will backfire on Kelly.
"We don't allow people to come in from the outside to come in and tell us who they think should be our representative. People from this district are the ones who's going to decide that," said Beale.
A spokeswoman for Chicago Mayor Rahm Emanuel said Monday afternoon that Emanuel had no role in Bloomberg's decision to spend so much money in the 2nd Congressional District.
Both mayors are strident gun control advocates.