Kelly, 56, easily won the special primary in February from a crowded field of candidates including former Congressman Debbie Halvorson. The main issue in that race quickly became gun control and Kelly, who was endorsed by President Barack Obama, agot a huge boost from New York Mayor Michael Bloomberg's super PAC, which supported her gun control stance. Kelly is in favor of an assault weapons ban and has vowed to be a leader in the federal fight for gun control.
Jackson resigned in November. In February, he pleaded guilty to charges accusing him of misspending campaign funds.