In Boutilier v. Immigration and Naturalization Service, 1966, the U.S Supreme Court upheld a decision to deport Clive Michael Boutilier, a Canadian citizen who had been living in the United States since 1955. The reason for his deportation was based on him being homosexual which at that time was considered as "psychopathic personality" under immigration law. This case is significant because it highlighted the discrimination faced by homosexuals during this period in American history. Despite having lived and worked in America for over ten years without any criminal record or issues of misconduct, Boutilier's sexual orientation alone was deemed sufficient grounds for deportation. In a split decision (5-4), the court ruled against Boutilier stating that Congress intended to include homosexuality within its definition of "psychopathic personality". This ruling remained until 1990 when Congress removed homosexuality from its list of excludable conditions.

The dissenting opinion in Boutilier v. Immigration and Naturalization Service argued that the majority's interpretation of the law was incorrect, specifically their understanding of "psychopathic personality" as including homosexuality. The dissenters believed this interpretation to be a misreading of Congressional intent when they enacted the statute, which was originally intended to exclude individuals with severe mental disorders from immigration rather than targeting sexual orientation. They also pointed out that at the time Congress passed this legislation, homosexuality was not widely considered a psychopathic condition by medical professionals or psychiatrists. Furthermore, they criticized how Boutilier had been treated during his deportation proceedings; he wasn't given an opportunity for psychiatric examination nor allowed legal representation until late in his case process - both factors contributing to an unfair trial according to them.