Bit of a tortured analogy but, whatever it is his right to block unwanted text as it is her right to “hang up on you”.
You have the right to speak......you, however, DO NOT have the right to be heard or be published.
Just a wild guess but I’m thinking she voted for Killary and is still a little upset about Ms Pants Suit not being in the White House?
I have always put it in another way; The 1st Amendment says you have a right to speak your mind, but, it also means “I DON’T HAVE TO LISTEN TO IT”.