CAMBRIDGE, Mass. — Former Vice President Joe Biden is urging college graduates to take up the “dirty business of politics” to change the trajectory of the world.

The Democrat made his comments at Harvard University’s Class Day on Wednesday.

Biden told Harvard’s seniors they’re graduating at a moment of great change and have an obligation to steer America “closer to where we want as a nation.”

He appeared to offer veiled criticism of Republican President Donald Trump, saying those who “play on fears and appeal to baser instincts” can still achieve political power.

But Biden said he believes today’s students are “the best-educated, most-talented, most-engaged generation” and are capable of tackling the world’s problems.

Biden served six terms as a U.S. senator for Delaware before becoming vice president under Barack Obama in 2009.