For all the talk about President Donald Trump's travel ban, it's still somewhat unfamiliar territory. After all, most presidents don't sign executive orders like the one he signed.
So, what's the historical basis for the executive order? To understand that, we should take a trip back to 1950.
That's when Democratic Sen. Pat McCarran proposed a bill giving the president power to suspend immigration when "the entry of any class of aliens ... into the United States would be detrimental to the interests of the United States."
The president at the time — Harry Truman — wasn't a fan. Even though he and McCarran were both Democrats, Truman vetoed the bill after Congress passed it in 1952.
McCarran wrote his bill at the height of McCarthyism, when concerns about Communism were running wild in Congress. And McCarran was one of the foremost anti-Communist policymakers.
Truman's veto rejected that McCarthyism, claiming: "The countries of Eastern Europe have fallen under the communist yoke — they are silenced, fenced off by barbed wire and minefields. ... We do not need to be protected against immigrants from these countries — on the contrary we want to stretch out a helping hand."
He added: "The idea behind this discriminatory policy was, to put baldly, that Americans with English or Irish names were better people and better citizens than Americans with Italian or Greek or Polish names."
Congress overrode that veto and the bill became law that June. Six decades later, the immigration debate sounds eerily unchanged.
Speaking about travel ban, CNN's Fareed Zakaria told viewers: "[Trump] chose to punish ordinary men, women and children who are fleeing terrorism and violence."
So, did Trump's travel ban overreach the authority set out by the 1952 law? That's a distinction that will now be up to the Supreme Court.