A portion of an anti-vaccine and anti-Asian message being circulated online.

SACRAMENTO —?The emotional debate over mandatory vaccinations in California public schools has taken an ugly turn, with racist tweets and images being circulated online by opponents.

The main target is State Sen. Richard Pan (D-Sacramento), who is also a doctor. He sponsored SB 276 — signed into law by Gov. Gavin Newsom on Monday —?which will crack down on doctors who write fraudulent medical exemptions from school vaccinations.

Proponents, including the American Academy of Pediatrics, the California Medical Association and Vaccinate California, argue that parents who refuse to let their children be vaccinated because of personal beliefs, rather than legitimate medical reasons, are endangering public health by increasing the spread of measles and other communicable diseases in the student population.

SB 276 and a companion bill are needed to “keep children safe from preventable diseases,” Pan said.

“This legislation provides new tools to better protect public health, and does so in a way that ensures parents, doctors, public health officials and school administrators all know the rules of the road moving forward,” Newsom said in a statement.

Anti-vax protesters delayed Senate debate on the bills for nearly two hours by shouting and pounding on walls and doors, according to KGET. In the Senate’s public gallery, protesters unfurled an upside-down American flag and chanted, “My kids, my choice.” Others were detained by police while blocking entrances to the Capitol.

Assemblymember Devon Mathis (R-Visalia), who voted against the legislation, said, “This goes past vaccines and is again a major government overreach … Our medically fragile children are what are at stake.”

An image posted by Christine Lee (@RN4Truth), inspired by communist Chinese propaganda posters, features an Asian man wearing a Mao jacket and holding a syringe. Underneath are photos of Pan; former State Sen. Ervin Yen, an Oklahoma Republican; former New Jersey General Assembly candidate Jennifer Chuang, a Democrat and a pediatrician; and Dr. Eve Switzer, an Oklahoma pediatrician of Chinese descent.

The text reads, “Authoritarians unite! That’s right, they’re all doctors-turned-politicians who are pushing draconian mandatory vaccination and anti-parental choice legislation in their states.

“Notice anything else about them? Hint: Guess where 80% of all vaccines sold in the U.S. come from. Are these doctors-turned-politicians actually vaccine sales reps? Makes you wonder.”

A tweet from former “Saturday Night Live” actor Rob Schneider reads, “My congratulations to the People’s Republic of Chinafornia, Chairman Mao Jr. (Dr. Pan), Comrade Lorena S. Gonzalez and Politburo Czar Ben Allen for SB 276 replacing doctors with state bureaucrats to make life-or-death medical decisions for California children. Gavin Newsom, veto SB 276.”

Gonzalez is a Democratic member of the Assembly from San Diego. Allen is a Democratic state senator whose district includes Santa Monica.

Some commenters found Schneider’s race-baiting odd since he is himself part Filipino.

Another tweet from “Cathy S-R” reads, “Dr. Pan … are you an American citizen? I’m super curious because if you truly are, you’d know we have something called the Constitution. And we are a free country last I checked. We have freedoms and rights some countries do not.”

The California Asian Pacific Islander Legislative Caucus said in a statement, “Racist rhetoric and imagery targeted at Dr. Richard Pan and other AAPI leaders is dangerous and can’t be tolerated. For too long, APIs have been seen as perpetual foreigners [which] ignores generations of contributions from our communities. We call on SB 276 opponents to publicly condemn the racist rhetoric by members of your movement.”

In addition to Pan, who is a vice chair, members of the caucus are Assemblymember David Chiu (D-San Francisco), chair; Assemblymember Al Muratsuchi (D-Torrance), vice chair; Assemblymember Ash Kalra (D-San Jose), parliamentarian; Assemblymembers Rob Bonta (D-Oakland), Ed Chau (D-Monterey Park), Kansen Chu (D-San Jose), Todd Gloria (D-San Diego), Evan Low (D-Cupertino), Adrin Nazarian (D-Van Nuys), and Phil Ting (D-San Francisco).

Diamond Bar City Councilmember Andrew Chou commented on Facebook, “Completely unacceptable. This is the very reason we should continue to cultivate and support more API candidates for run and win public office. We ARE Americans. We ARE leaders, and we are not going away.”

Pan has been the target of death threats and, last month, a physical assault. In downtown Sacramento, Austin Bennett — an anti-vaccine activist and conspiracy theorist who ran against Pan and launched a petition to recall —?was live-streaming when he shoved Pan from behind, sending him stumbling down the sidewalk.

“If he got what he deserved, he would be hanged for treason for assaulting children, for misrepresenting the truth,” Bennett said on the video.

Bennett was cited for misdemeanor battery and released by Sacramento police.

“I get harassed on social media, practically daily,” Pan told KQED. “We’ve got to tone down the rhetoric. Assaulting a public official is the next logical outcome of violence-inciting language.”