Minnesota Senate Majority Leader Amy Koch resigned from her leadership post the day after fellow Republicans confronted her about allegations that she had an "inappropriate relationship" with a staff member.

"We're here today with a lot of humility and some sadness and even shock," interim Senate Majority Leader Geoff Michel said Friday at a hastily called Capitol news conference.

Koch, the state's first female majority leader, was widely considered a hard-working and savvy campaigner who helped Republicans win control of the Senate last year for the first time in four decades. Her sudden resignation stunned Republicans, ending one of the shortest tenures for a Senate majority leader since 1933. The move will reshuffle the Senate leadership a month before the legislative session and less than a year before a high-stakes 2012 election in which Democrats are vowing to win back control of the Senate and the GOP will campaign for a proposed constitutional amendment that would preclude gays from marrying.

Koch could not be reached for comment Friday. Michel and the others refused to identify the staffer by name.

Michel and other senators said they had heard from several staffers over the past two weeks that Koch was having a relationship with one of her direct subordinates. They said that when they confronted Koch on Wednesday night, she didn't admit to the relationship or deny it.

"Her response to the conversation was ...'I think I need to consider resigning,' " said Assistant Senate Majority Leader David Hann, R-Eden Prairie.

However, Koch gave no indication she would do so right away.

Not long after the news conference, Michel announced that Michael Brodkorb, who was Koch's powerful communications chief, was no longer employed as a Senate staffer, effective Friday.

Senate leaders didn't return calls late Friday to determine whether Brodkorb's resignation was related to Koch's.

Brodkorb didn't respond to repeated phone calls and e-mails. He recently resigned as deputy chairman of the Minnesota Republican Party to assist Sen. Mike Parry's bid for Congress.

A quiet investigation

"There is no doubt that a manager cannot have such a relationship with someone they oversee, whose budget they oversee," Michel said during the news conference, with the Senate majority whip and two assistant majority leaders at this side. "It's pretty clear. That kind of relationship is inappropriate, it raises a conflict of interest and it creates ... an unstable, unsustainable work environment for our staff."

After receiving reports about the relationship two weeks ago, Senate leaders said they quietly began an investigation and explored the possible legal ramifications.

Then on Wednesday evening Michel, Hann and Sens. Claire Robling and Chris Gerlach met privately with Koch.

Gerlach said that "at no time did the majority leader confess or admit anything or deny anything to any of us" during the meeting.

"I think in the end there are probably only two people who really know what kind of relationship [it was] and how long it had been happening," Michel said. "It certainly had risen to a level within our Senate family that people were coming to us."

The Senate leaders said they were as stunned by Koch's quick resignation, though they thought she had made the right decision.

"I'm not sure we could have predicted 48 hours ago where this would end," Michel said.


Sen. David Senjem said he was "shellshocked" by the sudden turn of events.

"We need just a little ... time to get back on our feet," said Senjem, a former minority leader who said he would consider a bid to become majority leader.

On Thursday, Koch said she planned to serve out her term. Senate leaders would not say whether they thought that was appropriate.

"I would say she's probably got some more thinking to do about her future," Michel said. He said he didn't know if ethics charges should be forthcoming.

Koch, 40, is married and has a teenage daughter. The day she resigned, she betrayed no hint of scandal. In an interview with the Star Tribune, she joked, laughed and brushed aside questions about whether her leadership had been threatened from inside her caucus.

"This was a decision about me looking to the next option. That's what this is about," Koch said. "It's public service and it is not supposed to be forever."

In all, her term lasted less than a year.

During that time, she recruited and campaigned for Republican candidates, helping the GOP achieve its historic takeover of the Minnesota Senate.

She introduced more than two dozen new senators to the ways of the Legislature, handling freshmen enthusiasm and occasional freshman conflict. She also negotiated a hard-fought budget deal with DFL Gov. Mark Dayton and the GOP-controlled House that ended a three-week state government shutdown this past summer.

Senate Republicans will elect a new majority leader within two weeks. More than a half-dozen senators have already said they might seek the job.

Rachel E. Stassen-Berger Twitter: @rachelsb