3. Message overload. Democrats have been arguing they will be able to effectively use their financial advantage to discredit little-known Republican challengers with loads of opposition research on the airwaves. But in states with competitive gubernatorial and Senate races, voters will be so overloaded with advertising that they’ll have trouble sorting through all the noise — or, even worse for the Democrats, they may simply tune out all the negative messaging.

That will make it much tougher for House race advertising to have a significant impact in states like Ohio, Wisconsin, Pennsylvania, Nevada and Florida, just to name a few. If the attacks get lost in the clutter, the message will not be fully heard. The trajectory of the gubernatorial races in many of these states will play a significant role in whether House Democrats sink or swim, and needless to say, the upballot trajectory in most cases is not looking good for the majority party.