In the 39 months that President Obama has held office, party affiliation has swung 10 points against his party.
According to Rasmussen’s polling, at the end of the month in which Obama took the oath of office (January 2009), Democrats enjoyed an 8-point advantage in party affiliation — as 41 percent of Americans then said they were Democrats, while only 33 percent said they were Republicans. Eleven months later, a few days after the Democratic Senate’s passage of Obamacare on Christmas Eve, the Democrats’ lead had dropped from 8 points to just 1.5 (35.5 percent Democratic, 34 percent Republican). By the end of the month in which the midterm elections took place — 7 months after Obama had signed Obamacare into law — the Democrats had lost their advantage altogether and actually trailed the Republicans by a point (36 percent Republican, 35 percent Democratic). Seventeen months later, not much has changed — Republicans now enjoy a 2-point lead, with 35 percent of Americans identifying themselves as Republicans and 33 percent identifying themselves as Democrats.
At the end of October 2008, in the poll taken closest to that year’s presidential election, Rasmussen showed Democrats with a 7-point edge in party affiliation — the same margin by which Obama won.