I wish people didn't use the Hitler comparison because it always derails discussion (almost everyone is better than Hitler, even Trump). There are however enough other cases throughout history of people being elected and then becoming dictators.
It is the exact right comparison though. Conservatives failed to maintain power on their ideals. The weak party clings to power, and propels a populist into power. He scapegoats immigrants, and liberal ideas for the general malaise. The only saving grace is that he is old, and not genocidal.
People wouldn't be as familiar with the outcome if we were to discuss those other dictators. I'm certainly unaware of their parallels.