(Bloomberg) -- Leaders of the right-wing Proud Boys group who participated in the Jan. 6 insurrection signaled they’ll challenge conspiracy charges by arguing that “hundreds or thousands” of other rioters also coordinated activity that day and weren’t hit with such serious allegations.

Defendants including Ethan Nordean, who led Washington state’s Proud Boys chapter, should be allowed to seek evidence from the U.S. Justice Department to determine if people associated with unpopular groups are being singled out for harsher treatment, defense attorney David Benjamin Smith said Tuesday at a virtual hearing in federal court in Washington, D.C.

The First Amendment protects the right to associate with groups that “may not be beloved by the government and the rest of the country,” Smith said. Nordean was charged in March with conspiring with three other Proud Boys leaders to obstruct an official proceeding of Congress, which was meeting that day to certify Joe Biden’s election victory.

Smith argued the conspiracy charges represent so-called selective prosecution and enforcement, which is barred under equal protection provisions of the Constitution.

The lawyer also said he’ll challenge the government’s plan to have a U.S. Senate aide testify at trial about the process of counting electoral votes. The jury should able to decide for themselves if the certification -- which protesters planned to halt by storming Congress -- counts as an “official proceeding,” Smith said.

Assistant U.S. Attorney Luke Jones argued it’s too early in the overall investigation of the insurrection to know if any rioters who don’t belong to right-wing groups will also be charged with conspiracy.

“There’s no reason to think there won’t be other charges -- including conspiracy charges -- against others who worked in concert,” Jones said. It’s “not surprising” that people who belong to the same group might be charged with a conspiracy, he said.

The judge said he’ll rule later on the defense request to search for evidence that the groups were singled out. The same judge earlier denied the men’s motion to dismiss the criminal case.

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