This story was updated on Tuesday, May 26 at 3:45 p.m.

In important ways, America in recent years has become a less bigoted country. In today’s U.S. Senate, there is no equivalent to Jesse Helms, who during his 1984 reelection race filibustered a federal holiday for Martin Luther King and his 1990 reelection race aired an ad showing a pair of white hands crumpling a job rejection letter as the narrator declared that “they had to give it to a minority because of a racial quota.”

In today’s Republican presidential field, there is no equivalent to Pat Buchanan, who won the 1996 New Hampshire primary after having asked, “Who speaks for the Euro-Americans who founded the U.S.A.?” and having declared that “women are simply not endowed by nature with the same measures of single-minded ambition and the will to succeed in the fiercely competitive world of Western capitalism …. The momma bird builds the nest. So it was, so it ever shall be.” Even the politicians who still wish to deny gays and lesbians equal-marriage rights now insist desperately that they harbor them no malice.

To hear some conservatives tell it, the last group against whom one can practice socially acceptable bigotry is, well, them: white, straight, native-born, right-wing Christians, against whom the federal government is waging a “silent war,” as Bobby Jindal alleges, that may lead to the “criminalization of Christianity,” as Mike Huckabee warns.

But I suspect that if a presidential candidate trafficked in prejudice against conservative white evangelicals, his candidacy would abruptly end.

The same, sadly, does not seem to be true of appeals to suspicion of Muslims. Republican presidential hopeful Lindsey Graham said earlier this month that “Everything that starts with ‘Al’ in the Middle East is bad news.” (Al is the Arabic equivalent of “the”). Graham, it’s worth remembering, is running as the foreign-policy intellectual in the GOP field.*

Why do such comments attract so little outrage? Because while American politicians have become less overtly bigoted against African Americans, Latinos, Jews, women and lesbians and gays, anti-Muslim bigotry is still entirely acceptable, at least in the GOP.

Among Graham’s opponents for the Republican nomination is Mike Huckabee, who in 2011 said Christians shouldn’t rent space in their churches to Muslims because “Muslim group[s]” say “that Jesus Christ and all the people that follow him are a bunch of infidels who should be essentially obliterated.” And who this February declared that, “Everything [Obama] does is against what Christians stand for, and he’s against the Jews in Israel. The one group of people that can know they have his undying, unfailing support would be the Muslim community.”

Another likely contender is Rick Santorum, who last November accused presidents Bush and Obama of having given “all Muslims a pass” and in 2011 announced that equality “doesn’t come from Islam. It doesn’t come from the East and Eastern religions. It comes from the God of Abraham, Isaac, and Jacob.” (Evidently, Santorum thinks Ur Kasdim is a city in Pennsylvania.) They will all likely square off against Bobby Jindal, who earlier this year kept saying Europe contained “no go” zones from which non-Muslims were barred even after Fox News retracted the claim.

All these candidates walk in the footsteps of 2012 contenders like Newt Gingrich, who warned that, “Sharia is a mortal threat to the survival of freedom in the United States,” and Herman Cain, who ruled out appointing a Muslim to his cabinet. Neither Gingrich nor Cain lost significant support as a result of these comments. Nor have Huckabee, Santorum, Jindal, or Graham. Which is not surprising when one realizes that 39 percent of likely Republican Iowa caucus-goers see Islam as inherently violent. (Among Democrats, the figure is one-third as high).

To be fair, not all the Republicans running for president indulge in anti-Muslim bigotry. In 2011, Mitt Romney publicly rejected the idea that Islam is inherently violent. In New Jersey, Chris Christie nominated a Muslim attorney to be a superior court judge and even denounced the “gaze of intolerance that is going around our country” when it comes to Muslims.

Let’s hope Christie keeps denouncing Islamophobia on the campaign trail, and that other Republican candidates join in. Right now, the GOP field is often described as divided between conservatives and moderates or libertarians and social conservatives. With any luck, a public divide will break out between candidates who demonize American Muslims and those who defend their rights. In today’s GOP, sadly, that would constitute progress.

* This paragraph originally quoted a BBC report stating that Senator Lyndsey Graham had said, “I know Iranians are liars.” The BBC has now corrected that report to make clear that Graham actually said, “I know the Iranians are lying.”