Bernie Sanders at a campaign event in Maryland
Bernie Sanders at a campaign event in MarylandMark Wilson/Getty Images

Vermont Sen. Bernie Sanders officially announced his candidacy for President of the United States Tuesday.

Sanders made the announcement on Vermont Public Radio.

Sanders, an avowed socialist, first ran for president in 2016, when he challenged Hillary Clinton for the Democratic nomination. The former independent stunned the political world by posing a significant challenge to Clinton by winning 20 states during the Democratic primaries. Millennial voters showed particular enthusiasm for Sanders, who is now 77.

“Together, you and I and our 2016 campaign began the political revolution. Now, it is time to complete that revolution and implement the vision that we fought for,” Sanders said.

The Sanders campaign sent out an email to supporters stating that “our campaign is not only about defeating Donald Trump. Our campaign is about transforming our country and creating a government based on the principles of economic, social, racial and environmental justice."

Sanders joins a crowded and ever-growing field of Democrats seeking to challenge US President Donald Trump in the 2020 elections, including Kamala Harris, Cory Booker, Elizabeth Warren, Amy Klobuchar, Tulsi Gabbard, Julian Castro, John Delaney, Marianne Williamson, and Andrew Yang.