Such a designation could give law enforcement new tools to combat the groups. Numerous laws on the books give authorities the power to restrict the movements of gang members and enhance criminal charges against them.

But such a move raises legal issues because unlike with traditional street gangs, the underlying motive of these extremist groups is political expression rather than criminal enterprise.

Law enforcement experts say the groups that have been warring in the Bay Area for months — which include anti-fascists and those using “black bloc” militant tactics, far-right organizations such as the Proud Boys and the Fraternal Order of Alt-Knights, and white nationalist groups such as Identity Evropa — certainly share similarities with a street gang.