That's Ambers' view:
[V]oters have already conducted their referendum on the Obama economy, and made their conclusions about whether to vote for the president based on his economic performance. If they are persuadable, they are persuadable on other issues, issues that Romney isn't going to find much traction with. This is why doubling down on his core message and trying to turn out as many hardcore conservatives as possible might not be a bad tactical decision. In fact, it might be the only tactical decision available to him at this point.