This example has nothing to do with the First Amendment.
And you received your law degree where?
The First Amendment incorporates what the Supreme Court articulated as "the freedom of association," specifically the "expressive association" concept which protects certain activity within the sphere of employment, including the articulation of political and religious opinions, so-called "protected speech."
That simply says the government can't take away your right to free speech.
That's a vastly overbroad and essentially incorrect articulation of the First Amendment.
Employers are not restricted from firing people for saying or doing the wrong things.
Flat out wrong. You can prohibit employees from discussing politics or religion in front of customers. You could not, however, prohibit employees from expressing a
certain type of political or religious position, which is what happened in the subject example. This is why, for example, employees can not be prohibited from discussing pro-union opinions in the workplace.
For example, if an employee chose to make a public statement that was at odds with the positions of a particular company, they can certainly be fired for that.
Yes and no. It's just not that cut and dry, particularly when an
employer is involved. Had this been someone expelled from a private club for articulating a particular opinion, that would be different.
You might disagree with the action or find it too harsh or unkind, but there would certainly be nothing illegal about it.
Again, flat out wrong. Had this happened in the United States, given the circumstances described in the subject example, the terminated employee almost certainly would've had a strong case for legal action.
I stand by my original statement: I'm glad we have the First Amendment. This clearly is protected speech. Yes, it's an unpopular position, but it should be protected, just like saying "I believe in gay marriage" to a coworker should be protected.