American independents movement: Fewer identify with political parties

Washington (CNN)Americans are increasingly declaring themselves independent.

A new analysis by the Pew Research Center finds that 39% of Americans considered themselves politically independent in 2014, the largest share to say so across more than 75 years of polling data.
Americans who do align themselves with a party tilt Democratic, with 32% across Pew's 2014 surveys calling themselves Democrats compared with 23% Republican. Despite the shift toward independence, nearly 9 in 10 say they at least lean more toward one party over the other. Adding in these "leaners," 48% of Americans are Democrats or Democratic-leaning independents, 39% Republicans or Republican-leaning independents, leaving 13% who say they do not have a partisan tilt. Among registered voters, the gap between the parties narrows to just 5 percentage points: 48% lean Democratic, 43% Republican.
    The shift away from partisan affiliation has occurred during a sustained period of government distrust and distaste for partisan politics. In the last year, negative impressions of government have displaced the economy atop Gallup's monthly measure of the nation's most important problem. The polling organization also recently reported that for the first time in its history of tracking favorability ratings for the two major parties, positive feelings toward both dipped below 40%.
    Trust in government has hovered near historic lows in many polls, and approval ratings for Congress haven't been in positive territory in more than a decade.
    The shift toward more political independence has been driven largely by younger Americans. Among those under age 34 in 2014, 48% considered themselves independents, an increase over the last decade, while the trend lines on independent affiliation for older Americans are flatter for the same time period.
    Those younger adults who do favor a party are more likely to prefer the Democrats over the Republicans. Once leaners are included, 51% choose the Democratic side, 35% the Republicans.
    And that, notes Jocelyn Kiley, associate director of research at the Pew Research Center, reveals an important limitation to the shift away from partisanship. Independent identification, she said, "is not yet signaling that they're not voting for one party or the other."
    At the voting booth, Americans still wind up choosing between the Democrats and the Republicans, and shifting demographic patterns in the U.S. could lead to broader advantages for the Democratic Party over time.
    "Millennials are coming in as more independent," Kiley said, "but when you look at how they're voting and their leaned party identification, they're also the strongest generation for Democrats."
    The segments of the population that are growing most quickly - Hispanics, Asian-Americans, the non-religious, and those with college degrees - are far more Democratic than others, and in some cases, are becoming more Democratic.
    By contrast, the groups that have become more Republican - whites, the silent generation and white evangelical Protestants - are declining as a share of the population.