Senior Senate Aide Ed Failor, who reported to Senate Majority Leader Bill Dix, announced his resignation in a late afternoon press release. Failor's exit is effective immediately.
Failor later told The Associated Press he didn't want to be a "distraction" as Senate Republicans elect a new leader Wednesday to replace Dix.
"I worked for Bill Dix," Failor said. "I'm not going to be a distraction for this caucus, and the new leader deserves to put together their team. It's the right thing to do."
Failor had worked for the Iowa Senate Republicans since the end of 2012. The party took control of the chamber after the 2016 election.
Failor's departure is the latest shake-up in the chamber. Dix submitted a one-sentence resignation letter Monday, hours after the liberal political website Iowa Starting Line published a video showing Dix kissing a female Statehouse lobbyist at a Des Moines bar.
National experts say the kiss raises ethical questions, but Iowa legislative leaders had muted responses Tuesday about what, if any, steps they might consider to address such behavior.
The woman, a registered lobbyist for Iowa League of Cities, had a job that included protecting millions of dollars in property tax payments that lawmakers have considered taking away from cities. Her professional work involved swaying legislation in favor of her organization.
Dix, a married 55-year-old pumpkin farmer, had the power to decide which legislation reached the floor for a vote in the GOP-controlled chamber.
"You have to ask, 'Was the relationship purely personal, or were there professional matters discussed?'" asked Jordan Libowitz, communications director for Citizens for Responsibility and Ethics in Washington, a public policy group. "If so, was he more likely to push a legislative agenda on behalf of this lobbyist?"
The woman and her organization did not respond to separate requests for comment left Tuesday by AP. Dix did not respond to phone and email messages left Tuesday.
No state law dictates how an Iowa lawmaker must behave in or out of the Capitol. Legislators are mostly bound by chamber rules that they themselves approve. Those rules do not explicitly prohibit such relationships, though ethics rules note lawmakers should "inspire the confidence, respect, and trust of the public."
Sen. Jerry Behn, a Boone Republican who chairs one of the two ethics committees in the Iowa Legislature, said he was reviewing those rules.
"What should we do?" he said. "The short answer is, I don't know."
Scott Amey serves as general counsel for Project on Government Oversight, a nonpartisan watchdog group on federal government activity. Amey said Dix should release all records of communication with the lobbyist to prove he wasn't influenced.
"I don't think his resignation ends an inquiry into this," Amey said.
Republican Gov. Kim Reynolds didn't add clarity to the issue Tuesday. Her staff released a statement on her behalf.
"You cannot legislate morality," Reynolds said. "As I stated on Monday, Iowans hold their elected officials to a higher standard, and when Iowans place their trust in their elected officials, they must act accordingly."
A message for Republican leaders in the Senate was not immediately returned Tuesday. House Republicans declined to comment.
The incident comes just a few months after a former Republican senator made recommendations to improve the process for reporting harassment complaints at the Iowa Capitol. That ex-legislator, Mary Kramer, was asked to make the suggestions in response to how Dix and Senate Republicans responded to the fallout of a discrimination lawsuit by an ex-employee who said she was fired for highlighting misconduct in the office. That lawsuit, which went to trial last summer, led to a $1.75 million settlement in favor of the former worker.
Kramer, who declined to comment Tuesday, provided a roughly four-page document in January that included suggesting that "all constituencies active in the Legislative Branch must receive training regarding what constitutes inappropriate behavior and acknowledging in writing they have heard and understood the guidelines."
Sen. Charles Schneider, a West Des Moines Republican, on Monday indicated he was interested in taking formal action on Kramer's suggestions, including updating an employee handbook.
"I certainly want to see that it's updated to reflect all the recommendations that Mary made," he said.
Senate Democrats, in the minority, say that's not enough. Senate Minority Leader Janet Petersen, a Des Moines Democrat, said lawmakers must address the findings of an internal report last year that indicated Republican Senate staffers were unlikely to report misconduct because of fear of retaliation.
"Senate Republicans need to clean up house, and they need to address the toxic environment," she said.
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