Eduardo Munoz / Reuters Former House Speaker Newt Gingrich says the U.S. ought to investigate terrorists like it did Nazi sympathizers.

Former House Speaker Newt Gingrich (R-Ga.) on Monday suggested taking broader federal action to investigate and prosecute U.S. citizens with ties to terrorism in the wake of the nightclub shooting in Orlando, Florida, that left 49 people dead and 53 others injured.

Gingrich, who has been mentioned as a possible vice presidential running mate to presumptive Republican nominee Donald Trump, told Fox News that the United States ought to investigate possible "Islamic supremacists" the same way it sought to ferret out Nazi sympathizers during the 20th century.

Let me go a step further, because remember, San Bernardino, Fort Hood, and Orlando involve American citizens. We're going to ultimately declare a war on Islamic supremacists and we're going to say, if you pledge allegiance to ISIS, you are a traitor and you have lost your citizenship. And we're going take much tougher positions. In the late 1930s, President Franklin Roosevelt was faced with Nazi penetration in the United States. We originally created the House Un-American Activities Committee to go after Nazis. We passed several laws in 1938 and 1939 to go after Nazis and we made it illegal to help the Nazis. We're going to presently have to go take the similar steps here.

The Special Committee on Un-American Activities was formed in 1934 to investigate Nazi propaganda and organizations spreading propaganda inside the U.S. It later shifted its focus, investigating disloyalty and subversive activities by U.S. citizens. By 1945, however, the panel was largely focused on investigating purported communist ties -- using its power to subpoena and blacklist Hollywood actors, screenwriters and directors. It is commonly associated with Sen. Joseph McCarthy (R-Wis.), whose notorious witch hunts against purported communist agents earned him censure by the U.S. Senate.

In 2011, Gingrich said the committee was "absolutely" a good idea "when it was created."

The gunman in the Orlando shooting was Omar Mateen, an American citizen who reportedly declared his allegiance to the Islamic State militant group before carrying out Saturday night's massacre. Mateen was killed by a SWAT team. President Barack Obama has said there's no clear evidence that Mateen was acting as part of a larger terrorist network.

The mass shooting, the deadliest in U.S. history, prompted a stir in the 2016 presidential campaign over the weekend.

Trump responded with tough-sounding bromides but little else, calling for "strength" and "strong surveillance," more bombing in the Middle East and efforts to "knock out" the Islamic State's internet capabilities. He also implied, not for the first time, that Obama is somehow sympathetic or even connected to Muslim terrorists -- a charge that a House investigative committee on terrorist sympathizers, like the one proposed by Gingrich, might be tasked with looking into.

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims -- 1.6 billion members of an entire religion -- from entering the U.S.

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