In 1941, famed aviator Charles Lindbergh was one of the leading speakers for the America First Committee, arguing against US entrance into World War II. Despite his fame, he was an open antisemite, racist, and nativist who had openly spoken approvingly of Adolf Hitler and Nazi Germany!
In 1992, Pat Buchanan, former speechwriter for Richard Nixon and Ronald Reagan, ran for the Republican Presidential nomination against sitting Republican President George H. W. Bush, promoting antisemitism, racism, and nativism, and denying the Holocaust perpetrated by Nazi Germany. He promoted an overly nationalistic America First foreign policy, similar to Lindbergh a half century earlier.
Now in 2016, Donald Trump is running for President, and likely Republican nominee, and is a racist, nativist, misogynist, and Islamophobe, who is now promoting an America First foreign policy, similar to Lindbergh and Buchanan.
The concept of shutting out the world, ignoring alliances, and alienating other nations, including those who are natural friends, was damaging in 1941 and 1992, and is still so in 2016!