A federal judge on Wednesday questioned whether the obstruction of an official proceeding charge that has been levied against at least 235 defendants in Capitol riot cases is unconstitutionally vague. 

During a lengthy hearing Wednesday for the conspiracy case involving 18 members of the far-right extremist group Oath Keepers, U.S. District Judge Amit Mehta for the District of Columbia asked about the determinations prosecutors used to file a felony charge of “obstructing an official proceeding” of Congress. 

“Essentially, what you said is, ‘Trust us,’ ” Mehta said, according to The Washington Post.

“And that is a real problem when it comes to criminal statutes, to suggest, ‘We know it when we see it, and we’ll pick and choose when it is an appropriate exercise of prosecutorial discretion.’ ”

Defense attorneys, including David W. Fischer, who is representing co-defendant Thomas Edward Caldwell, have argued that the felony charge was not being properly applied to the case, claiming that the congressional certification of Electoral College votes did not meet the definition of an “official proceeding.” 

The felony charge, which has been brought against Capitol riot defendants in addition to other misdemeanor offenses, carries a maximum sentence of 20 years in prison. 

Defendants in at least eight of the hundreds of cases containing the charge have moved to dismiss the count, either arguing that the joint House and Senate session on Jan. 6 did not count as an official proceeding, that the law is vague or that it did not properly cover the alleged actions of the defendants. 

The Post reported Wednesday that Mehta told federal prosecutors that they must be able to differentiate between “corruptly” obstructing or influencing Congress and actions of trespassing or disorderly conduct. 

Mehta said, “The million-dollar question is: What’s the limiting principle?”

Assistant U.S. Attorney Jeffrey Nestler defended the charge Wednesday, arguing that the crime does not necessarily cover someone who simply shouts, “Stop this proceeding!” but instead says something like, “There’s a bomb under your chairs!”

“The objective here was not just to halt proceedings,” the federal prosecutor explained, according to the Post. “The objective here was to scare Congress into halting proceedings.” 

U.S. District Judge Rudolph Moss also expressed questions on the charge in a separate hearing last month, noting that the government must present a clear differentiation between obstructing an official proceeding and lesser charges that carry maximum punishments of six months in prison. 

Mehta, an Obama appointee, during Wednesday’s hearing also slammed Fischer for arguing in his motion to have his client’s case relocated that District of Columbia residents despise rural Americans' "traditional values.” 

"This brief — and I will be reserved about what I'm about to say — reads less like a legal brief than something you might read on a blog," the judge said. "And that's not acceptable. I expect better from you, I expect better from every other lawyer in this courtroom."