Last night Elizabeth and I were talking about the Gates case. Aside from the issues of race relations and racial profiling, there is another important issue that this case brings up.
Should cops be able to arrest you for being rude to them? Although I'm generally pro-police, the answer to this is unequivocally "NO". You have a right to be a jerk to a cop, as long as you aren't threatening. We as a society walk a fine line between civil rights and security. When security is not being threatened, civil rights MUST be maintained. This entire argument is fleshed out in great detail HERE IN THIS Reason.com article.
THIS ARTICLE on Forbes is a little longer and filled with lots of legalese, but it outlines in great detail why the arrest was probably a violation of the First Amendment.