During the past week, Congresswoman Michele Bachmann has been rebuked by Senator John McCain and other Republican leaders for her attack against a US State Department official, Huma Abedin, and her call to investigate and root out other "Muslim extremists" who may hold sensitive posts in the US government.
It is important to recall that this smear campaign directed against Muslims and Arabs didn't start with the letters about Ms Abedin, signed by Ms Bachmann and four of her colleagues. The problem is older and runs deeper.
This wasn't the first time members of the US Congress instigated a witch hunt targeting American Muslims or Arab Americans in government. Just three years ago, Congresswoman Sue Myrick and three Republican colleagues called on the House of Representatives' sergeant-at-arms to investigate the presence of "Muslim extremists" working as Congressional staffers.
And during the Bush administration, Islamophobes tormented a number of Muslim American White House appointees: among them, Suheil Khan and Ali Tulbeh. Even an anti-tax activist, Grover Norquist, came under relentless attack for his efforts to encourage conservatives to reach out to Muslim communities.
There are two factors, however, that made this most recent attack different. First, it appears that in picking on Ms Abedin, US Secretary of State Hillary Clinton's long-time aide, Ms Bachmann took the witch hunt a step too far. Having been by Mrs Clinton's side since the Clinton presidency, Ms Abedin is known and respected in Washington and beyond.
During the past two decades, she has been repeatedly vetted by the Secret Service, FBI and CIA. That Ms Bachmann would hurl bizarre charges and flimsy allegations without hard evidence, and based only on Ms Abedin's family's faith and where they had lived, was considered an outrage.
Personality also played a role, as Ms Bachmann has often provoked the Republican leadership. Many were infuriated by her attempt to co-opt the grassroots Tea Party movement, by starting and then declaring herself head of the "Tea Party Caucus" in Congress, and by the harsh attacks that characterised her quixotic presidential bid.
Ms Bachmann's former campaign manager, Ed Rollins, a former Reagan administration official, echoed Mr McCain's description of Ms Abedin as "an honourable woman, a dedicated American, and a loyal public servant". At the same time, Mr Rollins accused Ms Bachmann of a "grievous lack of judgement and reckless behaviour", suggesting that such behaviour had become expected from her.
Even with Ms Abedin's character, and Ms Bachmann's penchant for show-boating, it took a challenge from Congressman Keith Ellison, the first Muslim to serve in Congress, to force the issue into the open. The letters from Ms Bachmann and her colleagues were released a month ago. It was not until Mr Ellison raised his objections, and media began to ask questions, that attention was paid to Ms Bachmann's charges. In the end, the looney members of Congress who co-signed the Bachmann letters were left stripped of supporters, save for crackpot fringe groups.
So far, so good. But several underlying problems remain. The Center for Security Policy - the group that was behind the Bachmann letters, the earlier Myrick effort to investigate Congressional staff and the attacks on Bush-era appointees - is still spreading lies targeting American Muslims and Arab Americans. The CSP is a key element in what the Center for American Progress has termed the "Islamophobia network".
The CSP and its companion organisations are well-funded, and have established ties to law enforcement agencies, the conservative media and some parts of the conservative movement. Some conservative groups have ostracised the CSP, and some law enforcement agencies have begun to review training programmes, but over the years such groups have done real damage.
Thousands of law enforcement officials have been trained with their hate-filled material. Millions of Americans hear them as commentators on right-wing TV and radio networks and programmes. Their propaganda campaigns have fed a deep partisan divide on attitudes toward Islam, Arabs and the Middle East in general.
Part of the reason why several 2012 Republican presidential candidates indulged in anti-Muslim demagoguery during the primaries was because they were looking at the polls and playing to their base.
As important as it is to defend Ms Abedin and rebuke Ms Bachmann, this is not enough. Americans must commit to changing the way they talk about Islam and the Arab world. This is important, as Mr McCain observed, because "what is at stake in this matter is larger even than the reputation of one person. This is about who we are as a nation, and who we still aspire to be".
For Republicans, this challenge is particularly important because, as Mr Rollins noted, their party was founded on the grounds that it would fight "slavery and intolerance at every level".
James Zogby is the president of the Arab American Institute
On Twitter: @aaiusa