That's political speech, and specifically protected in California outside of work. If you fire your employee for political activities outside of work, you still have to pay them, because they're going to sue you for lost wages, and win.
Then you don’t know the history of the non-compete agreement in the tech industry.
For decades, people were wringing their hands and holding themselves back from living well because they couldn’t possibly work for another software company after Google, Microsoft, whomever - because the contract stated they couldn’t work for competitors.
Well, then States showed up and said “that’s not even legal”, and people stopped handwringing.
But before, it looked very much like this thread.
If I was working for a dentist, none of your questions would be viable (let alone reasonable) for the employer to be asking.
Sorry, not buying that’s for anyone’s good.