Having an electoral mandate is a necessary condition, not a sufficient one. If you don't follow your own laws and your own constitution, for instance, you're not a in a democracy, even if you have been elected. Precisely because you are elected under the assumption that you will follow the laws and constitution, not have unlimited power to do whatever you like until the next elections.

The Trump regime is still borderline, but I think it's fair to call Netanyahu a dictator at this point.