I found this interesting, as it is, at a minimum, seditious, and might be treasonous, since it is clearly suggesting the desirability of a military coup. That’s really outside of the notion of constitutional government and does not (I believe) fall into the category of “protected speech” under the First Amendment. Of course, I could be wrong, but it seems unlikely to me.
I also find this of interest because it seems likely that the intent was to call the sitting President a “Marxist,” rather than a “Marist.” After all, a “Marist” is, I believe, the appropriate title for a member of one of several Roman Catholic orders (Male and Female) which developed out of a Society of Mary founded in France about 1816-17. It seems unlikely that President Obama is likely to take much offense at being called a good, devoted Catholic, however untrue that might be. Calling him a “Marxist,” or a Muslim, of course, would seem to have the inflammatory quality, which the writer seems to desire, but there appears to be little evidence to support either of these charges. And, of course, neither is exactly illegal. It also seems possible that the writer (probably a male, since it was a Men’s room) fails to see any problem with the idea that a follower of Islam could, simultaneously, be a Marxist and a member of a Roman Catholic teaching order. I confess that seems unlikely to me.
I DO feel strongly about supporting the idea of freedom of speech, so I do think that this author MIGHT have the right to believe and speak (write) his opinions, although, as discussed above, I have reservations about sedition being “protected speech.”
Of course, it may be more to the point that people would (I certainly hope) not accept such statements as having much credibility since it’s so poorly written, or proofed, that it actually says things which don't seem to make much sense in support of ideas which seem questionable.
After all, if the writer can’t spell “Marxist,” or “Moron,” why should one give anything she/he says much credibility? This is an example of why I think language and writing matter (much to some of my student’s annoyance). Probably the most important thing we humans do is communicate, and we, apparently, do more of it than any other creature. That makes the need to accomplish it with a certain degree of precision and accuracy of some importance. Unhappily, that means that spelling, punctuation, word choice, etc. are of some importance.
Maybe what it all boils down to is that it’s often wiser to “engage the brain before opening the mouth.” Otherwise, it’s very easy to get into difficulty rather quickly.