The Republican conservative base -- defined as Republicans and Republican-leaning independents who say they are both socially and economically conservative -- is the smallest it's been since 2005, according to a Gallup poll released Wednesday.
Forty-two percent of Republicans now describe themselves in these terms, a 9-point drop from one year ago and a 15-point drop from 2012. The percentage of Republicans who describe themselves as socially and economically moderate or liberal has jumped 5 points in the last two years, reaching 24 percent.
Where do the rest of the Republicans fall on the scale? Twenty percent describe themselves as socially moderate or liberal and economically conservative. This group has remained relatively unchanged in the last six years. The fourth category, those that describe themselves as socially conservative but economically moderate or liberal, represents the smallest portion, making up just 10 percent of the party.
These findings indicate that Republicans are part of an overall national trend: a record number of Americans now describe themselves as socially liberal.
In fact, Americans are shifting left on a number of social issues. Same-sex marriage has reached a record level of support, as has marijuana legalization. Americans are also becoming increasingly less religious, according to a Pew Research study released in May.
Gallup notes that although the shift is significant, it is not unprecedented. But it may present a unique challenge to 2016 GOP candidates, as they now face a conservative base that is less than 50 percent of the party.
Gallup surveyed 1,024 adults between May 6-10 via live interviews on landlines and cell phones.