Trump risks breaking law if he uses US military to suppress riots and taps army general to lead protest response

1878 Posse Comitatus Act places strong guardrails against a president using active duty military troops to uphold civil laws on US soil

Donald Trump plans to establish a "central command centre" headed by Joint Chiefs of Staff Chairman Mark Milley in an attempt to "dominate" the streets in cities where protests over the killing of George Floyd have at times turned riotous.

Mr Trump has also endorsed a potential course of action laid out by Republican Senator Tom Cotton of Arkansas on Monday to send US army units to areas of the country where there is acute rioting, which would appear to violate laws governing the use of active duty military personnel to quell domestic unrest.

The 1878 Posse Comitatus Act places strong guardrails against a president using active duty military troops to uphold civil laws on US soil. Congress can waive the law, but it is not likely Democrats would cede such authority to Mr Trump given the politically and racially sensitive nature of the protests.

It's also unclear whether Mr Milley, an active US Army general, could legally lead Mr Trump's proposed command centre.

The command centre will work "in conjunction with the state and local governments" in charge of cities — such as Minneapolis, Atlanta, and Washington DC — where protests have devolved over the last several nights into violent clashes between demonstrators and police and led to widespread looting and vandalism, White House press secretary Kayleigh McEnany told reporters on Monday.

“There will be additional federal assets deployed across the nation,” Ms McEnany said.

Attorney General William Barr and Defense Secretary Mark Esper will also help steer the command centre's operations.

Mr Trump "wants to dominate the streets with the National Guard, with a police presence," Ms McEnany said, claiming the press had taken a comment from the president in a phone call with governors earlier in the day out of context.

In that phone call, the president underscored the fact that he is more focused on maintaining a message of law and order than he is on sympathising with the non-violent masses protesting police brutality.

"You have to dominate," Mr Trump told the governors.

"If you don't dominate, you're wasting your time," he said, adding that he believed most of them were "weak."

While Mr Trump has said he will "stand with" the family of Mr Floyd — who died last week in Minneapolis after police officer Derek Chauvin knelt on his neck and back for several minutes despite Mr Floyd's pleas that he couldn't breathe — the prevailing message from his Twitter feed in recent days and call with governors on Monday was that law enforcement must stand strong against violent agitators.

The president has said he will designate the loose collection of militant left-wing, anti-fascist demonstrators known as "Antifa" as a terrorist organisation and threatened to deploy US military units to areas of the country where protest have gotten out of hand.

Mr Barr has already ordered US Bureau of Prisons riot squads to DC and Miami to quell pockets of violence that have raged in those cities in recent days.

The administration is "looking at every tool in the federal tool kit for us" to shut down violent protesters, Ms McEnany told reporters on Monday.

"Ideally this would have been resolved at the state level. The states, after all, have police power embedded in the 10th Amendment. It is their responsibility to patrol their streets,” she said.

By Monday, governors of 23 states plus DC had activated more than 17,000 National Guardsmen, whose actions are controlled at the state level, to keep the peace at demonstration areas.

Mr Chauvin — the Minneapolis police officer who was videoed kneeling on Mr Floyd's neck, touching off the recent wave of activism against police brutality — was arrested last week and charged at the state level with third-degree murder.