Government has unlimited power and if you want to make bitcoin destroy then it is easy, the government will recruit experts to make bitcoin destroy, but I hope this is never done all government.
I think some counties have already tried their best to stop their people from using bitcoin, but still i do not think that they have become succeeded, i think that they still cannot succeeded to stop their people form using bitcoin, in my country our government instructed people to stop using bitcoin and other altcoin but still people are using it without any difficulties.