Senate officials have said Brodkorb's termination was proper because he was an "at-will" employee.

The federal lawsuit of a former Minnesota Senate aide who alleges he was fired because of his gender was narrowed Wednesday when a federal judge granted the state's request to dismiss three counts, including defamation allegations. Michael Brodkorb's discrimination claims — one alleging a violation of state law and one a violation of federal law — remain.

Brodkorb was fired in 2011 after Senate leaders discovered he was having an affair with then-Majority Leader Amy Koch. Brodkorb sued the state of Minnesota, the Senate, and then-Senate Secretary Cal Ludeman, claiming he was unfairly treated because female Senate staffers who carried on affairs were not punished.

Senate officials have said Brodkorb's termination was proper because he was an "at-will" employee.

Brodkorb sued last summer on 10 counts. Several invasion-of-privacy claims were dropped months ago, leaving just five counts relating to defamation and gender discrimination. The state had asked that three of those counts be dismissed.

On Wednesday, U.S. District Judge Susan Richard Nelson granted that request, dismissing two defamation claims and a third constitutional rights claim. The civil rights claim was dismissed on its merits and on procedural grounds, with Nelson saying Brodkorb's attorneys failed to assert a plausible claim for relief.

When it comes to the defamation claims: Brodkorb said Ludeman defamed him by publicly discussing the case and suggesting Brodkorb was trying to "blackmail" the state and "extort" money. Nelson dismissed those allegations, saying that while the words "blackmail" and "extort" were intemperate choices, they were made "in context of heated, back and forth negotiations between the parties."

She said a reasonable person would not interpret that Ludeman was accusing Brodkorb of committing the crimes of blackmail or extortion.

Nelson went on to say that Ludeman's statements were made in response to Brodkorb's demand for a settlement and a threat to expose other relationships among staffers at the Capitol.

"The larger contextual backdrop for these statements was the political arena, where speakers — even those from the same political party, as here — often engage in provocative or inflammatory speech," Nelson wrote.

The defense had also asked to dismiss the state of Minnesota from the lawsuit, as well as any reference to unnamed "employees" of the Senate. Nelson granted those requests, saying that including the state as a defendant was redundant, and no there were no allegations that Senate employees engaged in any conduct that could prompt a civil claim.

Dayle Nolan, the Senate's attorney, said Ludeman is also no longer a party to the case, because the claims naming him have been dismissed. Nolan said the Senate is the only remaining defendant.

Nolan said the Senate will request that the remaining two counts, the gender discrimination counts, will also be dismissed through summary judgment.

"The Senate remains steadfast in its position that there was no gender discrimination," Nolan said.

An attorney for Brodkorb did not return messages seeking comment.

Senate leaders from both parties welcomed the news.

"We've said all along these claims are without merit and the Senate has acted lawfully," said Senate Republican Leader David Hann. "We believe the courts will find the remaining claims to also be without merit."

Senate Majority Leader Tom Bakk said: "We will now take time to review the implications of this decision as we determine how the Senate will proceed and ultimately resolve this litigation. Our hope is to bring the remainder of the lawsuit to a prompt and satisfactory conclusion."

The Senate has spent more than $200,000 on legal bills to defend itself in this case.