But, realize that any time you spend defending yourself is not spent explaining how you're going to fix the problem. It may be unfair, and that's one of the nicest aspect of democracy : given that people in power keep changing, at some point they don't feel bound to the choices made by previous governments, even of their own party, and can spend time trying to fix problems.
No chance of doing so if you start by arguing.
Also, some of the problems are _hard_.