Ex-Rep. Rick Renzi (R-Ariz.) has failed in his bid to use the Constitution’s “speech and debate clause” as a shield against federal corruption charges.

A federal three-judge panel rejected Renzi’s argument Thursday in a unanimous, 45-page ruling, affirming the Justice Department’s authority to aggressively prosecute Members of Congress.

Federal prosecutors allege Renzi engaged in a quid pro quo deal, seeking to enrich himself from a real estate transaction while offering the sellers the promise of federal mining rights. Renzi has denied the allegations, and his lawyers at Steptoe & Johnson argued in court that the Justice Department’s corruption charges violated the protection the Constitution affords to legislative speech and activity.

But the 9th Circuit U.S. Court of Appeals disagreed. The appellate court acknowledged speech and debate protections can be abused and can lead to “reckless” and slanderous charges. However, the Supreme Court has made clear that those protections do not “make members of Congress supercitizens, immune from criminal responsibility,” the lower court concluded, quoting the high court’s ruling in United States v. Brewster.

The case has been closely watched because, had Renzi’s argument carried the day, the Justice Department’s power to pursue corruption charges involving elected officials could have been severely weakened.

In the 2007 case involving then-Rep. William Jefferson (D-La.), the U.S. Court of Appeals for the D.C. Circuit signaled a shift in the opposite direction, potentially watering down Justice Department powers. That court found that federal officials violated the protections that surround privileged materials when they raided Jefferson’s office as part of a corruption probe.

Thursday’s ruling appears to establish that, at least for the moment, the Justice Department remains within its rights when investigating corruption. Lawyers for Steptoe & Johnson were not available for comment.