Conservatives are turning on Trump over his 'dangerous' national emergency threat: National Constitution Center CEO
National Constitution Center CEO Jeffrey Rosen/MSNBC screen shot

National Constitution Center president and CEO Jeffrey Rosen told MSNBC on Tuesday that President Donald Trump's threat to declare a national emergency was costing the president support among the conservatives and libertarians that make up much of his base.

"I was a bit surprised to learn that we have imposed these national emergencies 53 times, and many are still in effect, because of things that have been happening after 9/11 or after Iran," host Ali Velshi noted. "How does the government evaluate this, because there are a lot of people on Capitol Hill who say we have to watch government doesn't go too far with these things."

"Some the most powerful critics of President Trump right now are conservatives and libertarians who are afraid 'hey, President Obama tried to do a version this with the DREAM act, and a future Democratic president could declare a national emergency and impose lots of environmental policies by fiat," replied Rosen. "This is the most dangerous and significant thing a president can do is to declare an emergency." He added that history was rife with similar moments, from Truman's attempt to seize the country's steel mills to Lincoln's suspension of habeas corpus during the Civil War.

"Anyone concerned about containing government power, on both sides, will be hesitant to allow the president on his own say so to invoke the army and to say that it's up to him to use military forces," Rosen concluded.

Watch the video below.