Philadelphia’s progressive District Attorney Larry Krasner told Democracy Now’s Amy Goodman on Thursday that any federal officers who break state law within the City of Brotherly Love will be arrested and prosecuted. His comments come in response to President Trump’s threat to expand the “totalitarian” assaults by his secret police from Portland, Oregon to other cities run by “liberal Democrats.”

While Krasner and other local law enforcement agencies likely possess the authority to arrest law breaking federal agents, should they?

Krasner acknowledged that federal officers have a right to enter the city, and often do so for agreed upon joint law enforcement activities, but argued that no one, including the President, has a right to violate state law:

The argument may be legally supportable, but the issue entails not only the question of whether local DAs and police have the authority to effectuate the arrest of miscreant federal agents but also of weighing the risk of potentially adverse consequences…

‘A rebellion against our deepest constitutional principles’

Krasner acknowledges that federal agents are welcome, when invited, to lawfully engage in specific joint law enforcement activities. Indeed, he said, his office or a local law enforcement agency will often step aside for the feds in the interests of efficiency. But it’s an altogether different issue when local leaders and agencies oppose federal intervention.

Former U.S. Solicitor General Neal Katyal, during a Wednesday appearance on MSNBC’s The Last Word, cited a 2000 Supreme Court decision authored by former Chief Justice William H. Rehnquist, a Nixon appointee. “Our constitution,” Katyal observed, “doesn’t generally permit a domestic federal police force.” At a minimum, in Katyal’s legal analysis, sending federal agents to our cities to conduct local law enforcement against the express opposition of state and city authorities requires Congressional approval. Trump neither sought nor obtained Congressional authority in this instance.

Katyal’s analysis is echoed within the 22-page decision handed down on Thursday by U.S. District Court Judge Michael H. Simon. In that case, the court issued a Temporary Restraining Order to prevent federal police from assaulting and arresting the journalists and legal observers who are lawfully covering protests in Portland, Oregon.

In response to the federal government’s argument that “journalists have no to right to stay, observe and document when the government ‘closes’ public streets,” Judge Simon replied that federal agencies “are not the agencies that ‘close’ state public streets and parks; that is a local police function.”

The court importantly added:

Katyal, who referred to the federal agents operating in Portland as “thugs”, described Trump’s federal police operation as a “rebellion against our deepest constitutional principles.”

In a formal statement quoted by Goodman, Krasner cited his own family’s World War II military service before expressing concern about the fascist nature of Trump’s federal assault:

Measuring risk v. reward

While technically legal, an attempt by local law enforcement authorities to effectuate an arrest of armed federal agents could be fraught with risk.

In a federal lawsuit, Oregon’s Attorney General Ellen Rosenbaum argued that when armed U.S. Customs and Border Protection (CBP) agents, without probable cause, snatched an innocent citizen, Mark Pettibone, off a Portland sidewalk and whisked him away in an unmarked car, those agents interfered with Oregon’s “sovereign right” to protect “people within its own borders from kidnap and false arrest.”

If Krasner is legally correct about the right of local authorities to arrest federal agents who break state laws, Oregon and Portland would have been operating within their legal jurisdiction if they had deployed a SWAT team to surround the CBP agents, secured Pettibone’s release and arrested the CBP agents.

But these are armed federal agents. What happens if they resist? Would an armed shootout between state and federal agents become the opening salvo in a new civil war? Would Trump exploit that event as an excuse to further accelerate his assault on democracy?

It’s a difficult call, especially given Katyal’s description of what is occurring in Portland right now as “a rebellion against our deepest constitutional principles.” At a minimum, however, Krasner and other local law enforcement should carefully consider the potential for a disastrous outcome, or at least lay out strict rules of engagement, before attempting to arrest federal agents.

Perhaps, the wiser course was the one applied by Oregon’s AG. Challenge the illegality of Trump’s totalitarian assault in a federal court. State and local authorities can then seek the identities of the miscreant agents during discovery in federal court proceedings, and subsequently go before a state grand jury to request indictments.