I think this is what he is referring to:
“April 11, 2024
Press Release
Earlier today, Congressman Anthony D’Esposito introduced the Define to Defeat Act. If passed, this act would apply the International Holocaust Remembrance Alliance (IHRA) Working Definition of Antisemitism to the enforcement of civil rights laws.”
https://desposito.house.gov/media/press-releases/congressman-desposito-introduces-define-defeat-act-bringing-clarity-legal
The working definition of antisemitism:
“According to the definition, anti-Semitism “is a certain perception of Jews, which may be expressed as hatred toward Jews,” and that anti-Semitism could take physical or rhetorical form and be directed at Jews as well as non-Jews, in addition to property and institutions.
The document lists 11 ways that anti-Semitism could take shape. They include calling for Jews to be killed, advancing enduring Jewish stereotypes about conspiracy and control, blaming Jews as a group for the actions of individuals or various forms of denying the Holocaust.
Six of the 11 examples have to do principally with certain kinds of rhetoric around Israel. They include:
Accusing Jews of being more loyal to Israel or to a global Jewish agenda than to their home countries.
Denying Jews the right to self-determination or calling Israel a “racist endeavor.”
Applying a double standard to Israel that isn’t applied to other countries.
Applying classic anti-Semitic smears, like the blood libel, to Israel.
Comparing Israel to the Nazis.
Holding Jews collectively responsible for Israel’s actions.
The definition says anti-Semitism “frequently charges Jews with conspiring to harm humanity, and it is often used to blame Jews for ‘why things go wrong.’”
https://www.jta.org/2021/01/15/global/the-ihra-definition-of-anti-semitism-and-why-people-are-fighting-over-it-explained
So Massie is basically right it would outlaw any criticism of Jews and Israel that falls outside whatever politically correct standards they create. It definitely goes against the First Amendment. It’s another hate crime law except this one is exclusively for Jews.
Amendment I
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances
Calling something antisemitic doesn’t make it illegal and doesn’t make the person making the antisemitic statement a victim or martyr