Representation in the House of Representatives is, and should be, based on population. However, the 538 seats in the Electoral College should be redistributed after every Presidential election based on percentage of adult citizens who cast ballots. The formula for distribution would be identical to that used for current redistricting, though this calculation would only affect Electoral College seats, not Congressional districts.
The purpose is to encourage states to register as many adults as possible (thus not suppressing any vote by creating registration difficulties) and then encourage states to create a more voter-friendly environment, thus establishing higher electoral representation in the next election for states which prove to be successful.