The FBI is feeling the pressure to be more proactive to guard against rising domestic terrorism, but is hampered by legal constraints, The Wall Street Journal reported.

According to the Journal, anything that would allow more rigorous intelligence-gathering on domestic threats could be stymied by the courts — and draw flack from Congress.

Domestic terrorism is not even a federal crime, though there are proposals now to make it one in the wake of increasing mass shootings, including back-to-back attacks in El Paso, Texas, and Dayton, Ohio, the Journal noted.

But for now, the FBI’s ability to open an investigation solely based on hateful speech or affiliation with known domestic extremists is severely curtailed because it is largely protected by the Constitution.

“I always advocated for [a domestic terrorism law], and think it would be very helpful from an investigative standpoint,” Michael Mullaney, who served as the Justice Department’s counterterrorism chief during the Bush, Obama, and Trump administrations, told the Journal. “Nonetheless, it’s not an easy problem to solve, because it would bump up against the First and Second Amendment.”

Others say different approaches could be used without passing new laws. 

For example, by treating domestic hate groups as “criminal enterprises,” the FBI can pursue federal racketeering, conspiracy, or hate-crimes charges that carry steep penalties, Adam Lee, a former high-ranking FBI official who oversaw hate-crimes cases and led the Richmond field office during the deadly white nationalist rally in Charlottesville, Vigrinia, in 2017, told the Journal.

Different does not always mean successful.

Barbara McQuade, a former federal prosecutor who teaches law at the University of Michigan, said she worked on a 2010 case against Michigan militia members who allegedly threatened to kill police officers — and charged them with “seditious conspiracy,” via a little-used post-Civil War law, the Journal reported.

The judge in the case shut it down, writing that “offensive speech and a conspiracy to do something other than forcibly resist a positive show of authority by the federal government is not enough to sustain a charge of seditious conspiracy.”

“Without a domestic terrorism statute, it’s difficult,” McQuade told the Journal.