President Donald Trump's ad hoc assemblage of a federal police force to send to the cities of his choice — without collaborating with state and local officials — is an overreach of power with political overtones and should be stopped.

In the case of Portland, it happened over the objections of both the mayor and Oregon governor. Other cities threatened with such action also have objected.

A key question is whether the federal officers are there to quell violence or inflame it. From the needless camouflage uniforms — they are not on the battlefield, after all — to their aggressive tactics, these agents seem to think they are at war. And who are the combatants? Some troublemakers, to be sure, but many who simply are exercising their right to protest, including phalanxes of middle-aged women wearing T-shirts that say "Summoned Mama," a reference to George Floyd's dying call-out to his dead mother.

As often is the case, the Trump administration presents mixed messages rather than a coherent, strategic plan. Acting Homeland Security Secretary Chad Wolf, faced with serious pushback, has painted Portland as an extraordinary case, with a level of violence and threat to federal sites that warrant his assemblage of Border Patrol and Customs agents — many untrained in quelling civil unrest — and U.S. marshals.

Trump, on the other hand, was candid about his true purpose. At a recent news conference, flanked by his Attorney General William Barr, he vowed that Portland was just the start of federal deployments to cities across the country, including Seattle, Albuquerque and Chicago. Seattle officials have already objected, while Chicago Mayor Lori Lightfoot is attempting to negotiate terms of engagement. "I've drawn a very, very sharp line," Lightfoot said in an recent TV interview. "We are not going to agree to or accept anything like what's happening on the streets of Portland ... . We're not going to have unnamed federal agents patrolling our streets, pretending to be the police, sweeping people off and denying them of their constitutional rights. That is not going to happen in Chicago."

But why is it happening at all? Police powers are reserved to the states under the Tenth Amendment. Trump should not, under the legal pretext of protecting federal property, march in to "dominate" cities to bolster his new "law and order" stance. He's even named his campaign — "Operation Legend."

In Minneapolis, hundreds of protesters gathered Thursday to signal their concern over potential federal involvement. Mayors of 16 cities signed on to a letter stating that "The unilateral deployment of these forces into American cities is unprecedented and violates the fundamental constitutional protections and tenets of federalism."

The one restraint exercised came from a district court judge, who has blocked federal forces in Portland from attacking, arresting or dispersing journalists attempting to cover the events.

The federal government has intervened before on occasion. But this is different. Trump has assembled what essentially is a federal police force, stitched together from agencies under his control, that he can deploy at will. That has not been the norm in this country, nor should it be.