The definition of terrorism usually runs along the lines of, engaging in acts to cause fear for the purpose of achieving political goals. So, stalking someone isn’t terrorism, but sending pictures of a politician in various locations with crosshairs drawn on them saying you will follow through unless/if they do x would be.

Now, the question becomes, are these arsonists setting fire to Tesla vehicles and showrooms because they want Musk to stop his political antics or because Musk is a giant asshole? I honestly think you could get reasonable doubt on that, provided you actually had a fair trial and weren’t dropped in a deep, dark hole somewhere.