Senator Rand Paul said Donald Trump’s reversal of a ban on local and state police using military equipment means Americans are “sacrificing their liberty”.
The Kentucky Republican slammed Mr Trump’s reversal of Barack Obama’s ban in a string of tweets.
He wrote that Mr Trump was forcing people to trade freedoms for an “illusive and dangerous, or false, security”.
The programme, referred to as the 1033 programme, had originally started in 1990 as a way for local authorities to combat drug crime, which evolved to using it against terrorism.
Mr Obama halted the flow of certain surplus military equipment – grenade launchers, bayonets, tracked armoured vehicles, weaponised aircraft and vehicles, and firearms and ammunition of .50-caliber or greater – to local law enforcement agencies in 2015 after the police response to the August 2014 protests in Ferguson, Missouri.
He said then: “We’ve seen how militarized gear can sometimes give people a feeling like there’s an occupying force, as opposed to a force that’s part of the community that’s protecting them and serving them. It can alienate and intimidate local residents and send the wrong message.”
The community had been angered by the police shooting death of Michael Brown, an 18-year-old black man, by white police officer Darren Wilson. Mr Brown allegedly robbed a convenience store and Mr Wilson shot 12 bullets in his pursuit of the unarmed Mr Brown.
Local police issued curfews and the governor forced them to turn over control of the crowds to state police.
Protestor run down and shots fired in Ferguson
“The police involved were equipped as if they were going to war, even though they were supposedly there only to protect the community and help maintain peace,” Newsweek reported.
Attorney General Jeff Sessions addressed the Fraternal Order of Police just ahead of the announcement and said Mr Trump is “he is rescinding restrictions from the prior administration that limited your agencies’ ability to get equipment through federal programmes, including life-saving gear like Kevlar vests and helmets and first responder and rescue equipment like what they’re using in Texas right now,” referring to crews involved in rescue efforts during Hurricane Harvey.
No widespread looting or violence has been reported from the affected areas of Texas.
“Those restrictions went too far,” Mr Sessions said about Mr Trump’s fulfilled campaign promise to police officers in the organisation.
Some police organisations have been putting pressure on Mr Trump to reverse the Obama order and cite the use of an armoured truck as an essential part of the response to the December 2015 mass shooting in San Bernardino, California.
The American Civil Liberties Union said in a statement: “tensions between law enforcement and communities remain high, yet the president and the attorney general are giving the police military-grade weaponry instead of practical, effective ways to protect and serve everyone.”
Mr Paul opposed Mr Sessions view, however, and tweeted that the programme “still needs to be funded” by Congress.
His tweets seemed to indicate that Mr Paul would bring up the programme as part of debate on the National Defence Authorisation Act, the legislation governing it.
The Senate’s next session is set to open the first week of September.