The election in November may well turn on decisions made long ago. After Labor Day, there is little campaigns can do to alter the fundamental physics of a race. The best campaigns simply play defense well. In a close race, whichever candidate is most adroit at handling the unexpected will probably find himself with an advantage.

Nonetheless, pay attention to how Barack Obama and Mitt Romney handle these three broad subjects: economic anxiety, foreign policy, and Romney's definition. 

The adjectives used to describe the economy post-convention are "anemic" and "persistent" — as in, persistent, anemic job growth.  Obama needs to change these adjectives even though he can't change the underlying facts. Simply put, the facts favor Mitt Romney's core argument: that Obama's had four years to fix the economy, and he hasn't. How can Obama change the adjectives?  Well, he can refine his argument. And he can hope that somehow, that new argument begins to gel. Given how well Bill Clinton did at the convention, I'm kind of surprised the Obama campaign isn't running ads right now featuring Clinton "arithmetic" sound bite. 

The problem, of course, is that economic anxiety is not a product of a couple of years of policy decisions. It's not even the result of the Great Recession of 2008. It's the combined result of 30 years of globalization, a widening wealth gap exacerbated by the collapse of the housing market, significantly rising health care costs, the enormous shift in the tax burden to the middle class — and so much more. It's sticky. It doesn't respond to economic conditions. Consumer confidence and the stock market may be more temporary measures of sentiment, but nothing (not even a sustained recovery), will alter the drivers of the American middle class' persistent economic pessimism. 

Right now, Obama has an advantage on foreign policy. This is a profound shift in our politics, and the result of very deliberate choices and narrative revising on behalf of the president. True, few voters seem to care, and it's true that many liberal Democrats wonder if the party has sold its soul to the devil by adopting the post Cold War counter-terrorism consensus that really began to develop in the second term of the Bush administration. But ever since the days of Amnesty, Acid, and Abortion, and the deliberate attempts by Republicans to eviscerate the Democratic Party's foreign policy core, a sense that Democrats can't handle adult decisions has hung over the party. Not anymore. 

Between now and the election, we know of one big potential test: if Israel decides to take action against Iran without the help of allies. The U.S. government doesn't know what Israel is going to do, although they are mollified somewhat that the Israeli security cabinet seems to be split. If Israel does decide to go it alone, Obama's response — whether the U.S. reluctantly joins the assault, how it responds rhetorically, how it contains Iranian blowback — could very quickly alter perceptions of his foreign policy judgment. One of Mitt Romney's earliest arguments was that Obama was in over his head. Nothing like a foreign policy meltdown to give that substance.

Substance? The election may hinge on whether Americans look at Mitt Romney and see someone who isn't a caricature. The GOP convention was not the disaster that pundits made it out to be, but neither was it an unalloyed success. Romney had a free swing at the bat, and by dodging specifics, asked Americans to define him based on the type of man that he was, rather than the type of president he will be. Both are important, of course, but the latter is arguably easier for Romney to carry, because his campaign fumbled the biographical angle from the start. Romney's attack today is that Barack Obama has no plan to turn the economy around and was given a four year chance to do it. But while Americans disapprove of Obama's handling of the economy and tell pollsters they like Romney's ideas better, they don't know what those ideas are, because Romney hasn't really told them. And the Democrats did a pretty decent job defining them in the breach last week. The major danger for Romney: He enters the debate season with voters growing more suspicious of his (undefined) policy proposals while simultaneously not having a good idea of who the guy is in his maw.