What happened historically is moot unless you also shift the historical landscape to how it is today. Though Texas is still very much red, it may well be purple in a couple elections. California meanwhile has dramatically shifted left since voting for the first Bush. Of course, even California at that much of a gap doesn't necessarily guarantee a victory (hopefully nothing can guarantee anyone victory), but it is a key piece to the puzzle of making elections easier. It's plausible that over time it will shift back as well, but the people pushing for the popular vote movement aren't thinking that way.