WASHINGTON (JTA) — A number of leaders of Jewish groups signed a public letter condemning “highly offensive” remarks targeting Muslims by two Republican presidential candidates.

The letter, published Dec. 21 in the Washington Post and posted on social media, cites George Washington’s 1790 letter to the Touro Synagogue in Newport, R.I., which said that the U.S. Constitution “gives to bigotry no sanction, to persecution no assistance.”

“Suggestions that a Muslim cannot serve as president, or that Muslims should be registered and their mosques closed, are un-American and un-Constitutional,” said the letter.

It referred broadly to “politicians, candidates and commentators” as making the suggestions, but those specific proposals were made by GOP candidates. Ben Carson, a former neurosurgeon, said he did not believe a Muslim could serve as president, and Donald Trump, the real estate billionaire and frontrunner in Republican polls, has said he would consider registering Muslims and shutting down mosques.

Among the 45 signatories, 12 are Jewish, including leaders of the Reform and Reconstructionist movements, a senior official at the Jewish Theological Seminary of the Conservative movement, a senior official of the Anti-Defamation League, and leaders of the New York Board of Rabbis and T’ruah: The Rabbinic Call for Human Rights.

Also signing were leaders of major Christian and Muslim groups and civil society leaders.