How would the American right have responded had Anders Behring Breivik been a Muslim? Luckily, we don’t have to guess. In the immediate aftermath of Friday’s terrorist attack in Norway, conservative Washington Post blogger Jennifer Rubin did us the favor of simply assuming that he was a Muslim. She then used the attack to denounce lawmakers who in the name of deficit reduction favor “huge cuts in defense” and to lambast President Obama for suggesting “that we can wrap up things in Afghanistan.”

But had Breivik actually been a Muslim, I suspect Rubin’s efforts to tie the attack to the Afghan war and the defense budget would have quickly been overtaken by the search for his American counterparts: homegrown Muslim terrorists. Conservative commentators would have ridiculed liberals for opposing Peter King’s recent hearings into American Muslim radicalization. They would have demanded that law-enforcement officials cease their politically correct pussyfooting and begin racially profiling Muslims (or dark-skinned people who look like Muslims). Some even would have have suggested that Norway had been naive to admit so many Muslims into the country and urged that we not make the same mistake. The media’s primary question in the wake of the Breivik attack would have been, Can it happen here? And conservatives would have answered, Hell yes.

So let’s ask that question about the real Breivik attack: Could an anti-Muslim bigot commit a large-scale terrorist attack in the U.S.? The answer is, Absolutely, because the same anti-Muslim bigotry that influenced Breivik in Europe is widespread here.

There’s actually been a lot of right-wing, extremist Christian terrorism in the U.S. in recent years. The biggest terrorist attack in U.S. history prior to 9/11—the 1996 Oklahoma City bombing—was carried out by Timothy McVeigh, a white ex-Army officer with ties to the militia movement. That same year, Eric Rudolph bombed the Atlanta Olympics to protest abortion and international socialism. The only major WMD attack of the “war on terror” era—the 2001 anthrax mailings—apparently was the handiwork of a microbiologist angry that prominent Catholic politicians were pro-choice. In 2009, anti-abortion militants murdered Wichita doctor George Tiller. (He already had been shot once, and his clinic had been bombed). That same year octogenarian neo-Nazi, James Wenneker von Brunn, shot a security guard at the U.S. Holocaust Memorial Museum. Last February, Andrew Joseph Stack, angry at the federal government, flew a small plane into an IRS building in Austin, Texas.

The attacks on Muslims have been smaller in scale. Last August, during the “Ground Zero” mosque controversy, a Manhattan man stabbed a cabdriver after asking if he was a Muslim. The following month witnessed an arson attack against the site on which a mosque was being built in Tennessee. This May, the words "Osama today, Islam tomorrow” were spray-painted on a mosque in Maine. But what makes a larger, Breivik-style attack possible is that terrorism usually stems from the intersection between militant ideology and mentally vulnerable people. That’s why people like McVeigh and Rudolph latched onto extremist militia and anti-abortion ideology in the 1990s. And it’s why their equivalent today might well be influenced by Islamophobia, the current obsession of America’s extreme right.

Islamophobia is at least as prevalent on the political right today as militia-style, anti-government conspiracy-theorizing was in the 1990s. Herman Cain, who according to a June Des Moines Register survey is running third in Iowa and who in February won the Tea Party convention’s straw poll, has said he would not appoint a Muslim to his cabinet or as a federal judge. He’s opposed the building of the Tennessee mosque whose construction site was the subject of last year’s arson attack. And he has said he became "uncomfortable" when he learned that the surgeon who operated on his liver was Muslim. More than a dozen states, mostly in the reddest parts of the south and mountain west, are considering banning Sharia. Tim Pawlenty recently shut down a Minnesota program that helped observant Muslims buy homes without violating Islam’s prohibition on collecting or paying interest on loans. And Newt Gingrich has warned that by the time his grandchildren grow up, America may be “dominated by radical Islamists.”

Some conservatives have condemned some of this. Even Rubin recently said that Herman Cain “lacks an understanding of the Constitution. And he certainly isn’t ready to be president.” But the criticism doesn’t remotely approximate the outrage that would have followed similar statements about Jews, Christians, African-Americans, or almost anyone else. It’s painfully clear that in today’s Republican Party, the price of publicly opposing anti-Muslim bigotry is higher than the price of fueling it. And somewhere out there, someone like Anders Behring Breivik is watching.