In addition to Ted's excellent answer as to why female circumcision is significantly different, you'd have a problem with multiple religious groups that practice it as a rite. Orthodox Jews are directly commanded to perform it
According to the Torah (Genesis 17: 9-14), Abraham was commanded by God to circumcise himself, all male members of his household, his descendants and slaves in an everlasting covenant.
The Torah (Genesis 16:14) also says: "Any uncircumcised male who is not circumcised in the flesh of his foreksin shall be cut off from his people; he has broken my covenant."
Christians are not required to be circumcised, but many American Christians adhere to it anyways. Some parts of Islam practice it as well.
Since there is no apparent (to those practicing it) long lasting harm to boys who are circumcised, this is one area where they would be a strong push back from the US religious community at large if someone were to suggest laws to make it illegal. Iceland faced a similar backlash
One in three men globally is thought to be circumcised, the vast majority for religious or cultural reasons. Many Jews and Muslims fear the issue of circumcision could become a proxy for antisemitism and Islamophobia, pointing to similar tensions over religious dress and the ritual slaughter of animals for meat.
Muslim and Jewish leaders attacked the proposal, while Cardinal Reinhard Marx, president of the Catholic Church in the European Union, said the bill was a “dangerous attack” on religious freedom. “The criminalisation of circumcision is a very grave measure that raises deep concern.”
There are no corresponding mainstream religious beliefs that mandate female genital modification of any kind.