Both long-term and short-term forces determine the outcome of U.S. presidential elections. Long-term forces include the state of the economy, voters’ satisfaction with the direction of the country and the level of stability in world affairs. Short-term forces include candidate speeches, political ads and presidential debates.

In 2008, the long-term forces — overwhelming dissatisfaction with the direction of the country, fatigue with eight years of a Republican president, fear over the financial meltdown — created an enormous tailwind for Barack Obama. He and his team ran a superb campaign, but the effect of that campaign was far more evident during his Democratic primary win over Hillary Clinton than during the general election. In the general, a mediocre campaign would have defeated John McCain given the forces at Obama’s back.

In 2012, the long-term forces are reversed for President Obama. Three-fourths of voters are dissatisfied with the direction of the country, unemployment remains a full percentage point higher than the highest a post-Depression president running for reelection has ever survived, and a majority of the country still thinks we are in a recession. Those forces create a strong headwind for the president’s campaign.