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 to 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 is occurring as more senior citizens are becoming 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 now more likely to identify themselves as Democrats by an average of three 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.