Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
We love to say that the Second Amendment protects the First. And to a certain extent, that's true... but it goes both ways.
The First Amendment isn't needed to protect uncontroversial thoughts. No one finds offense in a Yankees sign. (Well, except maybe BoSox fans.) No, the First Amendment is to protect the things that make us uncomfortable. Things we don't necessarily want to see or hear. And truth be told, we don't have to listen to them, or look at them - but the government can't stop their being said or printed.
The First Amendment won't protect someone from getting the tar beat out of them by an angry bystander, either. It only protects you from the government.
There is a long litany of court cases covering First Amendment decisions. Some of them are fairly common knowledge: Schenk, Brandenburg, Flynt, Skokie... these are all cases where speech that could be considered inflammatory, indecent, or discomfiting has been protected by the courts.
TJIC has not been accused of any wrongdoing. He has not been arrested. That pretty clearly does not pass the sniff test as written by Justice Holmes in Schenk v. United States (1919).
"The question is whether the words are used in such circumstances and are of such a nature as to create a clear and present danger that they will bring about the substantive evils that Congress has the right to prevent. It is a question of proximity and degree."
"I read some guy on the internet wrote '1 down 534 to go', so I thought it'd be a good idea to start poppin' Congresscritters." That's going to earn you a padded cell with a suicide watch and a regular dose of Vitamin H and some other happy pills. TJIC's statement, while arguably in bad taste, is highly unlikely to present a clear and present danger, or as written in Brandenburg v. Ohio, "is [not] directed to inciting or producing imminent lawless action, and is [not] likely to incite or produce such action."
"Imminent". "Clear and present danger".
Words have meaning. TJIC's words do not present a clear and present danger.
Thoughts and ideas; those are the things truly dangerous to a repressive state. Certainly, guns have their place, but if you believe that an armed rebellion similar to the 18th century is plausible, you are deluding yourself. Soap box, ballot box, jury box. Oh, the cartridge box still exists - always will - but the odds are decidedly stacked against you.
(Edit to add: Roberta says it far more eloquently than I did.)