The Senator for Vermont also said people voted for Mr Trump because they were in despair and not because they’re racist.
The 75-year-old was promoting his new book, “Our revolution: A future to believe in”, when he made the claims during an interview in front of a crowd of 1,000 people at George Washington University.
"I say to those critics, number one, that you can argue the exact reverse, that maybe I would have been elected President of the United States," Mr Sanders said, NBC reported.
He also claimed his campaign didn’t hinder Hilary Clinton’s attempt at beating Mr Trump.
"My campaign brought millions of people into the political process, the overwhelming majority of whom ended up voting for Hillary Clinton.
"Very few people in this country worked harder for Hillary Clinton than I did," he added.
The longest-serving independent in US congressional history also took aim at the Democrats, saying he feared for the future of the party.
"This is the debate we are going to have to have in the Democratic party, that debate is: which side are you on?
“Can you go out and raise substantial sums of money from the wealthy and Wall Street and other special interest and then convince the American people that you are on the side of workers and the middle class?” Mr Sanders said, according to ABC.
"Ordinary people have got to know that the Democratic Party has the guts to stand up to some very powerful people whose greed is destroying the middle class ... if we can’t do that I don’t see much of a future for the Democratic Party
“Or you do you finally have to say we are going to take on the oligarchy? That is a fundamental difference that exists between Bill and Hillary Clinton and myself," he added.
Mr Sanders also criticised President-elect Trump decision to hire alt-right figure Steve Bannon as his senior counsellor. He described the move as “unacceptable”.
"I call on Mr Trump to rescind the appointment he made of Mr. Bannon. A president of the United States should not have a racist by his side.
“The majority of people in this nation are not racist, not sexist, not homophobes. If we stand together, Trump will not be able to pass policies that are racist."
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