Bernie Sanders endorses Hillary Clinton for president Tuesday in Portsmouth, N.H. (Melina Mara/The Washington Post)

Bernie Sanders is planning to launch as many as three new organizations to continue the “political revolution” that began with his presidential campaign, a top aide said.

Sanders, who endorsed Hillary Clinton as the Democratic presidential nominee during a Tuesday morning rally in New Hampshire, sent a lengthy email to supporters shortly afterward explaining his decision and previewing his future plans.

“In the coming weeks, I will be announcing the creation of successor organizations to carry on the struggle that we have been a part of these past 15 months,” the senator from Vermont said. “Our goal will be to advance the progressive agenda that we believe in and to elect like-minded candidates at the federal, state and local levels who are committed to accomplishing our goals.”

Jeff Weaver, Sanders’s campaign manager, said Sanders is working to set up at least two, and possibly three, “sister organizations” to carry out those missions.

One will be devoted to policy formulation. A second will focus on recruiting and training candidates. And a third might engage in other political activity, possibly registering as a political action committee, Weaver said.

“We’re working out details right now,” Weaver said, adding, “This would have happened whether Bernie Sanders was elected president or not.”

Weaver said he expects the organizations to be up and running in a matter of weeks, with the aim of fully participating in the fall elections.

In his email, Sanders also acknowledged that not all of his supporters would be happy with his decision to endorse Clinton.

“I know that some of you will be disappointed with that decision,” Sanders said. “But I believe that, at this moment, our country, our values and our common vision for a transformed America, are best served by the defeat of Donald Trump, and the election of Hillary Clinton.”