Would you believe just 21.7%?
Yep, it's true...a candidate in a two-party race could win as much as 78.3% of the popular vote and STILL lose the election...legally and lawfully.
I ran a linear model to calculate the optimal campaign strategy, based on 2000 election and census data, and it turns out that our electoral college system allows an amazingly skewed balance of power. Some states have as much as FIVE TIMES the voting power per person than other states. For example, Michigan had about 381,000 voters per electoral college vote, while Wyoming only had 73,000.
One voter, one vote...it's a nice theory, but our system doesn't create the equity we think it does.
The complete numbers to prove it are here: http://craigfroehle.com/voting