Celebrities are people who have political views and there is nothing wrong with them sharing those opinions.
Some pretty novel ideas in there (three, I believe), no?
Unlike those people, however, I do not subscribe to the notion that celebrities ought to stick to entertaining us and remain silent on politics. While the lives of celebrities are quite a bit removed from those of the average citizen, at the end of the day, they are still citizens of the US. Whether to critique or support the opinions of others or rally people behind or in opposition to a politician or a piece of legislation, civilians have the right to speak their mind. Celebrities do as well. Being a world famous movie star, a television or social media sensation, or an icon of the music industry does not remove the right of these people to share their opinions with the world.
That said, just as celebrities share with civilians the right to share their opinions, like civilians, they also ought to be prepared for criticism of those opinions. Their right to speak their mind does not insulate them from criticism when they say shitty things. And celebrities often say Very Shitty Things. Azaelia Banks has said many shitty things. Ted Nugent has built a second career out of saying shitty things. Mel Gibson famously opened his mouth back in 2006 and out poured shitty anti-Semitic things.
Nicole Kidman can now add her name to the list of celebrities who have said shitty things: