From the Pew Research Center:
The Republican Party’s struggles in appealing to young people have been well documented. And even those Millennials who do identify as Republicans or lean toward the GOP are decidedly less conservative than older Republicans.
Overall, Millennials (currently ages 18-33) are the most liberal age group. In our report on Political Polarization in the American Public, we used a scale based on 10 political values questions about the role of government, the environment, homosexuality and other issues to measure ideological consistency. This survey of more than 10,000 Americans finds that, on this scale, Millennials are considerably more liberal than other generations: About four-in-ten Millennials are mostly (28%) or consistently (13%) liberal in their views, compared with 15% who are mostly (12%) or consistently (3%) conservative (44% are ideologically mixed). Older generations are progressively more conservative.