During a rally against a California bill making vaccines mandatory for school children, a Republican lawmaker from Fresno galvanized the crowd by invoking forced internment camps.

Senate Bill 277 would make vaccination a condition of enrolling in private and public schools, which opponents have castigated for depriving children of an education. That argument temporarily derailed the bill in the Senate Education Committee and was featured prominently in Tuesday’s rally.

“I wouldn’t call it a concentration camp,” said Assemblyman Jim Patterson, R-Fresno, “but they’re suggesting (children) go some place other than public school.”

Later in his speech, Patterson said that he “thought we apologized for internment camps,” an apparent reference to the separation and confinement of Japanese-Americans during World War II.

Asked after the rally to explain his comments, Patterson said it was a “bad choice of words” but reiterated that SB 277 is “excessively punitive.”

“I think the penalty that is in this bill, which is the isolation of these children – this is an expulsion from private and public school. That smacks of the kinds of things that are the beginnings of discrimination that can go very ugly places,” Patterson said.

Incendiary rhetoric has marked the debate over SB 277 before. Robert F. Kennedy Jr., a prominent critic of the Centers for Disease Control and Prevention who has traveled the country warning about vaccines, apologized after suggesting that injuries linked to vaccines were causing a “holocaust.”

Another speaker at Tuesday’s rally, Minister Tony Muhammed, referenced the biblical tale of the Pharaoh ordering the murder of first-born babies and drew a parallel to the Tuskegee Syphilis Study, in which the U.S. government experimented on African-American men.