I'm not all that sure the Republicans are going to get much traction on this one. After all, the left has been crowing for nearly a decade now about how various Republican electioneering efforts "stole" the past two elections.
The trick, I suppose, is just how much evidence there is, and whether there are actual laws being broken. Unlike activists on the other side, I know both parties do absolutely everything in their power, legally or otherwise, to ensure a win for their side. It just seems that the Republicans are better at keeping just barely in-bounds. Will the Democrats prove as adept? Hard to say. If history is any guide the Republicans seem to get busted long after the score, while Democrats seem to cough the ball up long before they're anywhere near the goal line.