There are many reasons that our nation’s political discourse has become coarsened over the years. But, here is the main one: willful stupidity.

According to a new poll by the Pew Research Center [1], 20 percent of Americans now believe that President Barack Obama is a Muslim. More than a third of self-identified conservative Republicans, believe Obama is a Muslim, which is more than the percentage of Republicans who vote in your average primary election.

During the campaign, Sen. John McCain was at a Town Hall meeting when someone in the audience suggested that Obama was a Muslim. McCain corrected the person then and there. Who among the Republican leadership will stand up now and correct the record?

We can disagree about many things in a democracy, indeed such disagreement is the very stuff of democracy. But, there is no arguing with stupidity. As Cong. Barney Frank once said to a woman holding a photo of Obama defaced to make him look like Hitler, it is better to argue with one’s dining room table than to argue with such stupidity.

Update: Cathy Grossman treats this issue at her blog at USAToday [2]. She raises the important point that the use of the word "muslim" may now have become a slur.