The problem with the concept is not that it's inherently a bad idea to temper democracy, it's that it will become just another way of gerrymandering: Make it easier/harder to people you agree/disagree with to vote their mind to stack to deck in favour of a given outcome.
The two are one and the same. Every time you introduce a crude new exception to the rule, you create an imbalance and complexity. Simple is better than complex. Organic is better than artificial. Otherwise emergent behavior is always a way to hack the system (e.g.: gerrymander). The beauty of one vote per person is that it's simple. Now, in the US, things get complex when we start talking about swing states, the fact that 3/4 of voters don't give a crap, etc. You can easily have a system where a few thousand Ohio residents decide who becomes president. However, the more complexity you introduce the more loopholes you will create.
