Following months of speculation, Vermont Senator and former contender for the Democratic presidential nomination Bernie Sanders formally endorsed his one-time rival Hillary Clinton at a New Hampshire rally on Tuesday.

Sanders pledged to give the former Secretary of State his full backing, following concerns by Democrats the tumultuous primary season would leave the party divided, harming Clinton’s general election campaign.

Sharing a stage with Clinton, Sanders called upon supporters to vote for the former First Lady and promised to “do everything I can to make certain she will be the next president of the United States.”

Sanders, a marginal figure in the US Senate prior to his presidential bid, has been given a number of appointments within the Democratic National Committee, installing campaign staff and supporters who have pushed the party’s platform to the left on key issues like socialized healthcare, the national minimum wage, the Israel-Arab conflict, and climate change.

Standing under a banner reading “Stronger Together”, Sanders said the new Democratic Party platform would continue the “revolution” – an allusion to the enthusiasm among younger voters sparked by the 74-year old democratic socialist.

“Together, we have begun a political revolution to transform America and that revolution continues. Together, we continue the fight to create a government which represents all of us, and not just the one percent – a government based on the principles of economic, social, racial and environmental justice.”

“This campaign is about the needs of the American people and addressing the very serious crises that we face,” he continued. “And there is no doubt in my mind that, as we head into November, Hillary Clinton is far and away the best candidate to do that.”