Another way to understand many Speech and Press Clause cases is to look at what the government is attempting to regulate. If the government is trying to regulate the content of expression, rather than the “time, manner, or place” of expression, its regulation will almost always violate the 1st Amendment. The particular test that the government has the burden of meeting is called “strict scrutiny.” That is, whenever the government tries to regulate the content of speech, courts will examine the case very carefully (they will “strictly scrutinize” it) and demand that the government demonstrate that the regulation is: 1) necessary, and 2) has a compelling government interest. By “necessary” courts mean that the regulation is the “least restrictive” way to achieve the government’s interest – essentially it is the only way to do so. As for what constitutes a “compelling” interest, the bar is similarly high: issues like national security are compelling; routine government business is not.
It is useful to look at what kinds of expression are not protected. Over the years, courts have identified several exceptions to the 1st Amendment’s protections. Each exception represents a judgment on whether the speech in question is either of limited or no value, or if it causes enough harm to justify regulating it. Each exception is thus controversial, and each shares a common problem: How do we define the boundaries of the exception? Put differently, which speech remains protected by the 1st Amendment, and which does not?