When anti-circumcision activists first proposed a ballot measure to criminalize the procedure in San Francisco, many people laughed at the absurdity of it all.

No one is laughing now.

Last week, news broke that a leading proponent of the ban created comic books and trading cards featuring anti-Semitic caricatures reminiscent of Nazi-era propaganda. With that, the circumcision debate took an ominous turn.

The comic book in question, “Foreskin Man,” features a chiseled Aryan superhero in the title role and his battles against loathsome Orthodox Jewish villains, including one called Monster Mohel, who appears to derive no greater pleasure than mutilating baby boys.

Can anyone say “blood libel?”

Matthew Hess,  the San Diego–based creator of “Foreskin Man,” denies he has anti-Semitic intentions with his work, and that he is only looking out to protect human rights.

Either he is a liar or a fool. History is replete with imagery of Jews as bloodthirsty demons, followed by countless pogroms, ghettoization, exile and genocide; he should know better than to revive such images.

But no. Hess may think he’s looking out for babies. He is in fact propagating the worst in mankind — a hateful, injurious and inciting perspective that poisons what might otherwise have been a civil debate.

It is important to note that Hess does not speak for all in his movement. Some of his Bay Area colleagues have distanced themselves from the “Foreskin Man” comics available online.

Lloyd Schofield, the leading figure behind the proposed San Francisco ban, said June 8 on the KQED’s “Forum” with Michael Krasny that the comic book was “inflammatory,” that it “evokes the wrong message and that’s why it was never posted on our Web pages.”

Hess also wrote legal language for a proposed ban, which the San Francisco activists adopted. It includes fines and/or prison time for doctors or mohels who perform a circumcision in San Francisco, as well as for parents who permit it.

Schofield may not like the comic, but he apparently has no problem with the comic book creator and his goals.

As those leading the fight against the ban have said in recent weeks, the odds of this measure passing Nov. 8 are slim to none.

That does not mean Jews and others standing up for religious freedom and parental rights should relax. This measure must be soundly defeated. Especially now, as unmasked anti-Semitism has entered the picture, a crushing defeat in November is more important than ever.

We are confident San Franciscans will do the right thing.