The problem in getting electoral reform anywhere is that the Goernment is always made up of people who have won under the existing system.

I imagine that if your Democrats were to lose a couple of times more, with it being apparent that a different system of voting would have given them the election, some pressure for reform would build up. But the example of what has happened in the UK suggests that, as soon as they won an election, they'd forget all about that kind of thing, and stick with the system that had given them victory.