Vermont Senator Bernie Sanders promised in a video address on Thursday night to continue his political revolution, declining to concede the Democratic nomination to Hillary Clinton despite losing a majority of votes to his rival.

Still, he vowed in his video address to do whatever he could do to help Clinton defeat Donald Trump in a general election, promising to work with her to “transform the Democratic Party.”

“Election days come and go. But political and social revolutions that attempt to transform our society never end. They continue every day, every week and every month in the fight to create a nation of social and economic justice,” Sanders said, speaking in his video address from Burlington, Vermont. “That’s what the political revolution is about and that’s why the political revolution must continue into the future.”

Continuing the clarion call of his campaign, Sanders said the Democratic Party must commit to raising the minimum wage to $15 an hour, pay equity, opposing the Trans-Pacific Partnership, expanding Social Security and breaking up the large Wall Street banks, policy positions that he and Clinton disagreed over during the course of the primary.

Sanders charts a risky path by deciding not to concede. He may anger party leaders as well as the base of the Democratic Party, who will begin to see him as an obstruction to Clinton despite his significant loss, and denying the first woman major-party nominee in the country the full claim to that title.

But his vow to help defeat Donald Trump comes as comfort to some Democrats and Clinton aides, who see his aid as crucial in the fall to holding onto the White House.

“The major political task that we face in the next five months is to make certain that Donald Trump is defeated and defeated badly,” Sanders said. “We cannot have a president who insults Mexicans and Latinos, Muslims, women and African-Americans.”

And in a hint to his willingness to cooperate, he said in the coming days he would join in the effort. “And I personally intend to begin my role in that process in a very short period of time,” Sanders continued.

Clinton won the primary with more than 15 million votes, around 3.5 million more than Sanders, and beat Sanders in pledged delegates with 2,219 compared with Sanders’ 1,832, a margin of nearly 400, according to the most recent count by the Associated Press. She won in a majority of states with high voter turnout and where independents could vote.

Sanders has promised for months to continue waging his campaign until the Democratic convention in Philadelphia in late July where he will challenge Clinton to adopt a series of policy proposals. He has called for the end of the superdelegate system, in which party elites untied to a democratic vote chose their favored candidate, and open primaries.

Sanders’ video address comes two days after Clinton and Sanders met on Tuesday night at a hotel in Washington DC to discuss eventually reconciling and uniting the party against Trump.

“I look forward, in the coming weeks, to continued discussions between the two campaigns to make certain that your voices are heard and that the Democratic Party passes the most progressive platform in its history and that Democrats actually fight for that agenda,” Sanders said in his address.

In 2008, Clinton conceded the primary to then-Sen. Barack Obama three days after the final primaries in Montana and South Dakota. Sanders, however, has less fealty to the Democratic Party and is committed to implementing a progressive platform and opening up elections to his followers.

Talk among his aides in recent days around contesting the convention has all but ended, and it appears unlikely he will aim to convince errant superdelegates to support his candidacy as he had once promised.

Some of his demands are outside of Clinton’s control. Whether primaries are open or closed, for example, is often decided by the state parties and is something the Democratic National Committee and has little input on. And the superdelegate system would have to be undone through widespread consensus in the Party.

Sanders inspired a generation of younger voters with his call for a more equitable society and projected a message of hope. Sanders, always cantankerous and combative, nonetheless inspired voters who saw him as high-minded and ethically untarnished after three-and-a-half decades in politics, first as mayor of Burlington, Vermont then as congressman and then to U.S. Senator.

It is clear that Sanders continues to long to control the tenor and the issues of the race. So far, he has pushed Clinton to adopt positions she may not have otherwise taken, including opposing the Trans-Pacific Partnership, opposing the Keystone Pipeline and formulating a robust Wall Street regulation plan, among others.

He punctuated his address with a call to action to his supporters. “The political revolution means much more than fighting for our ideals at the Democratic National Convention and defeating Donald Trump,” Sanders said. “It means that, at every level, we continue the fight to make our society a nation of economic, social, racial and environmental justice.”

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