Of course he still has the legal right to do it. The US hasn't gone so far yet, as other western countries have, to ban "hate" speech, and he hedged his arguments well enough that it would be hard to ban that kind of talk outright without exposing that you really don't care about the arguments, but that it's really about that he's daring to make them at all. That's why, in my opinion, he draws so much seething hatred - he was too careful about hedging and inviting discussion for the left to be able to dismiss him easily as a dumb retrograde hate monger, but they didn't want to address the arguments on the merits either (yes, I'm aware that there were exceptions, no need to list them, this is about the left as a whole). His speech has been effectively banned because he's been made a pariah and dismissed.
Of course the left hasn't completely won yet, so he's found a home in some parts of the right. But that's not the point, it's about what the left ultimately wants, and what we should expect if it wins. This serves as an example - the left is happy and comfortable when certain controversial points are suppressed and their advocates exiled.
"Would you force Googlers to work with someone they disagree with so strongly that they cannot be civil?"
Why can't they be civil? Is there a line where uncivil behavior is permitted because someone's thoughts offend you?