Could Bernie Sanders run against Elizabeth Warren in 2020 presidential race?

Sanders' former campaign manager asks: "Who can beat Trump in 2020?"

“The question is who can beat Trump in 2020, how we can put together the type of coalition from the folks who have taken it over and I think that is what the senator is weighing,” Weaver said during an interview with ABC News.

“I am confident that whoever runs there will be progressive standard-bearer who will be able to galvanize this grassroots energy.”

Weaver added, “Whoever wants to run for president should run."

“I think, the more the merrier,” he said.

Weaver sat down with ABC News to discuss his new book, “How Bernie Won,” in which he urges the Independent Vermont senator to run again in 2020 after detailing the launch and unexpected success of Sanders’ campaign from his perspective.

In his book, Sanders also recounts times his team felt the Democratic Party was actively working against Sanders campaign. He dismisses arguments that Sanders’ run could have hurt Hillary Clinton’s chances, and states repeatedly that the senator would have beaten President Trump in a general election two years ago.

“To the extent our campaign bears any responsibility for Trump’s victory it is that we did not defeat Hillary Clinton,” he writes in the book.

“As an empirical matter,” he added, “She did not win and so Bernie Sanders’s chances of winning empirically were as good as hers or better.”