The Republican Party fell from favor shortly after President George W. Bush's second inauguration as more and more Americans turned against the Iraq War. Then when Hurricane Katrina hit in August 2005, gas prices soared, and Americans widely criticized the Republican-led federal government for a miserable response to the disaster. Of course, one year later, Democrats surged back into control of Congress, with Republicans posting a dismal 35% favorable rating to close out 2006, according to Gallup.
The GOP slide didn't end there, however. Just before the 2008 election, Gallup found that only 34% of Americans viewed Republicans favorably, compared to 61% who viewed the party unfavorably, the worst rating Gallup had found since at least 1992.
Democratic Party favorability is also on the rise, though the party still posts a slim net unfavorable. In the Gallup poll, 46% of Americans viewed the party favorably, versus 47% who viewed it unfavorably. That's an improvement from the party's all-time worst split of 41% favorable to 54% unfavorable that Gallup measured shortly after the health care bill passed in March 2010.
The rising numbers for both parties are a reflection of Americans' improving impression of Congress in general. Following the economic collapse, Congressional approval sank to record lows at the end of last year--just 13% of Americans approved of the job Congress was doing in a December Gallup poll, the worst mark ever since Gallup began tracking that figure in 1974--though it has rebounded slightly to start 2011.
The Gallup poll was conducted January 14-16 among 1,032 adults nationwide, It has a margin of error of 4.0%.