I don't think we can discount at all the techniques used to keep people from voting or how we marginalize votes. Districting/gerrymandering is done by both parties. Voter ID laws are leading to Drivers License Office closing in places known for civil rights abuses. My own state has limited early voting and voting locations after years of more open elections. ALEC is actively trying to change local electoral laws from winner take all to proportional in the states it benefits republicans. It's proof that the voting booth Is the key to change but to suggest if people just voted things would change is a pretty naive view of elections.