Well it seems that you can't see the difference here. The difference being that Howard changed his position later and openly took it to an election and changed the legislation; where as Gillard changed her position directly after an election and changed the legislation. If Gillard later changed her position and took the Carbon tax to the next election, it would be equivalent, but she did not. This is why Labor and the Greens can't be trusted because they only believe in our democratic system of governance and administration when it suits them. This reinforces the common occurrence of why dictators throughout history are usually socialists like Hitler, Mussolini, Mao, Stalin, Kim etc etc.
Now if you can't see the difference, then that is your problem.