ST. PAUL — A fired aide’s lawsuit tied to a Minnesota Senate sex scandal means the episode will echo throughout the campaign season, creating a political hazard for majority Republicans and a delicate situation for Democrats, too.

Michael Brodkorb sued Monday over his dismissal, which came after the senior GOP communication adviser’s affair with then-Senate Majority Leader Amy Koch was revealed last December. Even before the wrongful-termination case wound up in court, the Senate had already spent $85,000 on lawyer fees related to the firing.

Despite Republicans’ desire to move beyond the scandal, the top GOP senator is vowing to fight the lawsuit rather work toward a negotiated settlement. The case was assigned Tuesday to Ramsey County District Judge John Guthmann, an appointee of former GOP Gov. Tim Pawlenty.

While no initial hearing date has been set, the state and other named defendants have a few weeks to file a written response to the claims. Witness depositions also lie ahead. Brodkorb’s lawyers say they intend to look into allegations of other Capitol affairs where those involved kept their jobs, hoping to make the case that he was treated differently.

So, as Republicans gear up to defend their narrow majority, there will be regular reminders of a serious ethical lapse in their upper ranks.