The Democrats currently have a popular vote advantage in Presidential elections.
For Mitt Romney to have won in the Electoral College he needed the national popular vote to shift a net 5.4%, this would have netted him FL (lost by 0.9%), OH (lost by 3.0%), VA (lost by 3.9%) and either CO or PA where he lost both by 5.4%. Thus, although he lost the popular vote by "only" 3.8% he actually would have needed a much bigger margin in the popular vote to have won in the Electoral College. Thus in close race the Democrats could win in the electoral college while losing the popular vote by as much as 1.5%. A similar result occurred in 2008, McCain lost the popular vote by 7.3% but would needed a net shift in the popular vote by 9.5% to have won in the Electoral College (although a shift of 9% would have caused a tie and thrown the contest to the House).
So what will happen to the Electoral College after 2020? Current projections of population growth for each state by the Census Bureau suggest this Democrat's advantage will vanish.
(see
http://www.centerforpolitics.org/crystalball/articles/the-future-shape-of-the-house/ ). Seven states will lose 1 EV each and 6 will gain a total of 7, with a net shift towards GOP states of 5.
Thus, if current trends continue, a GOP candidate would "only" need to hold the Romney states and add OH, FL, and VA to reach the minimum needed to win, 270 Electoral votes.
