Man, I am sympathetic to the free speech argument and I agree that the right has been getting shafted in that department, but this does seem pretty close to the "don't yell fire in a crowded theater" exception. This was not a protest in the democratic sense. It is a shameful day for the country.
This is way beyond "don't yell fire in a crowded theater," which was an action considered to be outside the protection of free speech because it presented a "clear and present danger." That standard was later restricted further, and is now "imminent lawless action." The President's actions appear to blow right past "clear and present danger" and explicitly call for "imminent lawless action."
That was not a protest. It was a planned and coordinated terrorist mob attack on the US Capitol, and successfully breached it. The first such successful attack since 1814.
Trump and allies have been communicating the date and requesting this behavior for weeks. Anybody surprised at the result should be deemed mentally incompetent.