Essentially, it's all semantics in the end, little more than splitting hairs.
No. The reason why these two words exist is that they mean two different things. So, it's more than just semantics. It is in the hands of the globalist enemies of the US that "protectionism" is now a dirty word and has been used by them as a weapon to shut up, not to enlighten. Just like "racism", "xenophobia, or "homophobia".
Protectionism isn't about shielding something from harm but from competition.
Well stated. Except that there are two kind of competition: one that is fair and by the rules and, then, there is China - a predator who will steal, cheat, back stab, manipulate, and spy. The US globalists, who love that arrangement because it is not they who carry the ultimate burden of unfair trade practices, love to throw "protectionism" around to shut down any fact-based debate. Hence, Trump is stupid, his tariffs are evil and may start a trade war. No f***king kidding! That war has been going on for decades with only one side doing all the shooting. And it wasn't us.