After years of legal wrangling over whether his discrimination lawsuit against former Sen. Mark Dayton (D-Minn.) passes constitutional muster, it appears former staffer Brad Hanson will get his day in court.

In a unanimous opinion handed down Monday, the Supreme Court declined to rule on an appeal put forth by the Office of the Senate Chief Counsel for Employment seeking to dismiss Hanson’s case, which was filed under the Congressional Accountability Act.

“We’re really pleased with it,” Hanson’s attorney Richard Salzman said of the opinion. “Obviously, the court only addressed the procedural issues, but this is certainly a win for us.”

In the lawsuit, originally filed in 2003, Hanson claims he was improperly fired after he asked for time off to have heart surgery. Specifically, Hanson is suing the one-term Senator for violating the Americans with Disabilities Act and Family and Medical Leave Act.

Dayton also violated the Fair Labor Standards Act by failing to pay him overtime, the former staffer claims.

Dayton repeatedly has denied Hanson’s accusations.

Senate Chief Counsel for Employment Jean Manning, who represented Dayton at the April 24 Supreme Court argument, said Monday she will prepare to defend Dayton in district court, where the lawsuit will now begin.

“We said all along that we are confident we will win this case, and I’m still confident we will,” Manning said.

In the appeal, Manning argued Members are protected against such lawsuits under the Constitution’s Speech or Debate Clause, which grants them immunity for actions related to their official duties. In effect, Manning argued that staffers act as a Member’s “second self,” taking on duties lawmakers themselves do not have time to do.

Accordingly, “the Member has to have complete discretion in selecting who these employees are and in managing them,” Manning told the court.

Both the District Court and U.S. Court of Appeals for the District of Columbia rejected those claims and ruled the case can move forward. But because those court decisions did not specifically rule on the constitutionality issue, the Supreme Court lacks jurisdiction to even put forth a ruling, Associate Justice John Paul Stevens wrote in the court’s opinion.

“The District Court’s order does not state any grounds for decision, so it can not be characterized as a constitutional holding,” Stevens wrote in the opinion’s syllabus. “Moreover, neither the Court of Appeals’ rejection of the Office’s argument that forces the Senator to defend against Hanson’s allegations would necessarily contravene the Speech or Debate Clause, nor that court’s leaving open the possibility that the Clause may limit the proceedings’ scope in some respects, qualifies as a ruling on the Act’s validity.”

The court also declined to rule on whether CAA cases become moot once a lawmaker leaves office. Chief Justice John Roberts did not participate in the consideration or decision of the case.

Salzman, who argued for Hanson in front of the court, said he was not surprised by the opinion, as several of the justices addressed the jurisdiction issue during the April argument.

And while he was pleased with the decision, Salzman said that it would have been helpful if the court had ruled on the matter in order to make future CAA cases more clear.

“I’m sure this issue will be revisited,” Salzman said.

When the justices decided to take up the case earlier this year, several Members of Congress got involved — to support Hanson.

In March, Senate Majority Leader Harry Reid (D-Nev.) and Minority Leader Mitch McConnell (R-Ky.) pushed through a resolution ordering the Senate Legal Counsel to file a friend-of-the-court brief on behalf of Hanson, pinning Senate lawyer against Senate lawyer.

Reps. Barney Frank (D-Mass.) and Christopher Shays (R-Conn.) also filed a friend-of-the-court brief, arguing that the CAA was passed by Congress to specifically serve as a way to address such claims.

It could be years before a decision on the case is finalized, but both parties said they were optimistic about their chances.

“Brad will get the chance to tell his story to a jury, which is all we ever wanted,” Salzman said. “We’re really at the beginning now.”