Perlstein, citing Ribuffo:

Anti-Semitism in America declined after World War II. But as Leo Ribuffo points out, the underlying narrative — of a diabolical transnational cabal of aliens plotting to undermine the very foundations of Christian civilization — survived in the anti-Communist diatribes of Joseph McCarthy. The alien narrative continues today in the work of National Review writers like Andrew McCarthy (“How Obama Embraces Islam’s Sharia Agenda”) and Lisa Schiffren (who argued that Obama’s parents could be secret Communists because “for a white woman to marry a black man in 1958, or ‘60, there was almost inevitably a connection to explicit Communist politics”). And it found its most potent expression in Donald Trump’s stubborn insistence that Barack Obama was not born in the United States.

I’m glad more people are saying this, but I’m still kind of baffled this wasn’t obvious.