Following the discovery of the Rep. Mark Souder affair, the Indiana Republican has announced his resignation amidst stories of Tracy Jackson, a part-time aide in his northern Indiana district office, being identified as the mistress.

Souder, an eight-term congressman, announced today during a press conference in Fort Wayne that he was resigning, effective Friday.

“I am so ashamed to have hurt the ones I love. I am sorry to have let so many friends down, people who have worked so hard for me,” he said.

Tracy Jackson has been identified as the mistress, a part-time aide who is still employed by Souder’s office. Also married, Jackson handled communications for Souder in a northern Indiana district office and periodically traveled with the Congressman.

She came on staff in Souder’s office in December 2004, earning $533.33 that year. This year, she earned $12,542.70.

Souder gave no details about the affair during his press conference, saying only, “I sinned against God, my wife and my family by having a mutual relationship with a part-time member of my staff. In the poisonous environment of Washington, D.C., any personal failing is seized upon and twisted for political gain. I am resigning rather than put my family through a painful drawn out process.”

Souder has been married since 1974, and has three children and two grandchildren. With his seat now vacant, Indiana Gov. Mitch Daniels will now need to either call for a special election or wait until the November ballot.

While working for Souder’s office, Tracy Jackson and Mark Souder made several videos discussing various subjects, including this video about abstinence education.