"Anti-American" is ideological rhetoric which is intended to engender fear, hatred and division among the citizens of this nation.  It is equating a difference of political opinion with treason.  It is drawing craven ideological lines between which Americans are "real" and which are not.  It is what Joe McCarthy did.  It is what Michelle Bachmann, Nancy Pfotenhauer and, by extension, John McCain et al. are doing.  Their rhetoric flies in the face of the fundamentally inclusive ideals on which America was founded and, as such, they are not allowed to designate anyone, save themselves by way of their own actions, as "anti-American."

Socialism is about state control of the means of production.  If you can't explain what this means or how it relates to what you're discussing, you aren't allowed to call anything "socialist."  If you are a Republican and you cannot explain how this relates to a recent law, voted on affirmatively by your Presidential candidate and signed into law by your President, which allows for potentially extensive nationalization of private sector debt-assets, you are not allowed to use the words "socialism" or "socialist."

Islam is an Abrahamic faith akin to Judaism and Christianity.  The First Amendment of the U.S. Constitution, prior to establishing protections for free speech and peaceable assembly, establishes freedom from state imposed religion or any restriction by the state on the free exercise of religion.  "Anti-American" is using "muslim" as a slur, just as is so when "jew" is used in such a manner.  If you do not believe in the separation of church and state or the free exercise of one's chosen faith, you hold an ideological point of view which is "anti-American" by definition.

We will have our political differences.  We will have vigorous debate about these differences.  We will have hard fought electoral contests.  At times, we may not find ways to agree.  But what we cannot have is a bellicose intolerance of difference.  We have far too much in common, far too much at stake to define ourselves in this way.