Are Muslims in America assimilating or not?

Since today is the anniversary of 9/11, let's take a moment to see how well Muslims are assimilating in American society.  The General Social Survey (GSS) asked respondents, "Consider a person who believes that Blacks are genetically inferior. If such a person wanted to make a speech in your community claiming that Blacks are inferior, should he be allowed to speak, or not?"

In my view, a core value of the American system is free speech.  If you don't believe in allowing people to state controversial opinions in public, you're not much of an American.

Here are the percentages in favor of free speech by religion.  Many American Muslims are blacks--I excluded them since we would expect many of them to oppose free speech for people with messages that make blacks look bad:

Of all religions, Muslims are the least supportive of free speech.

Have attitudes among Muslims improved or worsened over time?  I divided the data into two periods: 1) pre-2010 and 2) this decade:

Unfortunately, support for allowing someone with controversial racial views to speak in public has fallen among Muslims in this decade from 50.0% to 31.8%.  Not good.