Driving is dangerous, when you are driving there is always a chance you will harm yourself and others. Vanity license plates take your attention away from your car and the road. You end up wondering how to decipher that license plate or thinking about the statement the owner is trying to make. A second of distraction can be devastating on the road. We the people need to say no to all vanity license plates and make the roads just a bit more safer.
A license plate serves a purpose. It is for law enforcement purposes. It is help to identify vehicles and drivers. A license plate is not the time and place to make a determination of politics or a political statement. It distracts the public and law enforcement from the purpose of a license plate and public protection.
Controversial is quite difficult to define for the majority.
What you and I see as different is not nearly as important as one's freedom to express their opinions, albeit respectfully.
However, it's a consideration that license plates in general are distracting as they're reflective aluminum signage mounted to the front and rear bumpers of a vehicle— but if you were to ban them, you'd have to go so far as to consider banning vehicle decals (bumper stickers)of any kind.
Controversial vanity plates are not a distraction, at least not any more than any other license plate. Vanity plates are stupid. All it tells me is the person driving the vehicle is a goofy attention getter that has a very small opinion of himself. Those plates should be outlawed, just to tick these people off.
I can understand objections against controversial vanity plates. However, the problem with denying "controversial" vanity plates is that it's hard to define controversial. I have seen religious (Christian/Muslim)-themed vanity plates before, so why is that allowed, but other religious-themed vanity plates are a distraction? Either deny all religious plates, or allow all of them.