2. The Presidential Effect
Midterms are often seen as a referendum on the sitting president. Generally a popular president’s party will fare well, whereas an unpopular president’s party will pay for the public’s displeasure. In 2004, the public’s disapproval of the Bush administration translated into a big win for Democrats in that year’s midterm election. This year may see the same, as President Obama battles a fledgling approval rating, Republicans seem primed to retake the Senate.