Democrats have regained their edge in party affiliation after being essentially tied with Republicans for two years, according to Gallup

Forty-seven percent of the public identified as Democratic in 2012, compared to 42 percent who identified as Republican.

Party identification became a partisan issue during the 2012 campaign, with many Republicans arguing that mainstream polls were sampling too many Democrats. 

The core groups identifying as Democratic (31 percent) and Republican (28 percent) have not changed significantly. The shift is among independents: the number of Democratic-leaning independents is growing while the number of Republican-leaning independents is shrinking. Notably, while the number of independents usually shrinks in an election year, it stayed high in 2012 at 40 percent. 

Democrats generally lead in party affiliation, and their lead in Gallup is down from a 12-point edge in 2008. Republicans haven't led since 1991, the first year Gallup surveyed.