Young adults have typically identified with the Democratic Party, but those ties have become stronger since 2006.
The Gallup Poll finds that 54% of 18-to-29-year-olds on average since 2006 have aligned themselves with Democrats compared with 36% who identify with the Republican Party.
From 1993-2003, the gap among young adults wasn't as wide. Gallup's analysis of its polls taken over the years finds that 47% of 18-to-29-year-olds, on average, identified with Democrats compared with 42% for Republicans.
President Obama dominated among young voters in the 2012 election, winning 60% of 18-to-29-year-olds compared with 37% for Mitt Romney, according to exit polls. Obama did even better in 2008, capturing 66% of voters under 30.
Gallup says the trend among young adults occurs as more senior citizens become Republican. One major reason for the shift in party preference: The United States is becoming more racially and ethnically diverse. At the same time, young adults who are non-Hispanic whites are more likely to identify themselves as Democrats by an average of 3 percentage points.
What's the bottom line? "The GOP may find itself in an increasingly weak position against the Democrats unless it can broaden its appeal to younger and non-white Americans," writes Jeffrey Jones of Gallup.