Sen. Bernie Sanders is set to announce he will run for president in 2020, three years after fighting the Democratic primary race against Hillary Clinton, according to reports.

Independent senator Sanders, 77, plans to announce his presidential bid imminently, Yahoo News reports.

Early polls of the race have shown him as one of the top candidates in the Democratic primary field.

And a source told the website: 'What the senator has this time that he didn't have last time is he is the most popular elected official in the country right now. That's light years away from 2016 when very few people knew who he was.'

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Sen. Bernie Sanders is set to announce he will run for president in 2020 three years after fighting Democratic primary race against Hillary Clinton, according to reports

Early polls have shown him as one of the top candidates in the Democratic primary field

Sanders, right, nearly defeated Hillary Clinton, left, in the 2016 contest for the Democratic nomination and was widely expected to try for the White House again

His 2016 campaign was considered a success, even though he fell short to the eventual nominee, Hillary Clinton, left

Sanders forcefully denounced President Trump as a 'racist' on Martin Luther King, Jr. Day in South Carolina, a crucial presidential primary state.

Attending remarks at an NAACP event in the Palmetto State's capitol, Sanders said that 'a president is supposed to do is to bring us together,' yet Trump is 'trying to divide us up by the color of our skin, by our gender, by the country that we came from, by our religion.'

'Today we talk about justice and today we talk about racism, and I must tell you it gives me no pleasure to tell you that we now have a President of the United States who is a racist,' the senator asserted.

The assault on Trump was the clearest signals to date that Sanders was likely seek the Oval Office again in 2020.

Sanders, an independent senator, nearly defeated Hillary Clinton in the 2016 contest for the Democratic nomination.

He was widely expected to try for the White House again, even though this race would pit him against progressive allies like Hawaii Rep. Tulsi Gabbard and Massachusetts Sen. Elizabeth Warren.

His 2016 campaign was considered a success, even though he fell short to the eventual nominee, Hillary Clinton.

Initially, Sanders was considered a longshot, but he did manage to win primaries.

Sanders won a large enough chunk of the votes that he gained a following within the Democratic Party, forcing it to adopt a number of his positions.

Sen. Bernie Sanders, left, and House Speaker Nancy Pelosi, right, walk into an event with furloughed federal workers amid the partial government shutdown earlier this month

He was forced to apologize to women who were sexually harassed on his 2016 presidential campaign and thanked them 'from the bottom of my heart for speaking out.'

The New York Times reported that several women on his 2016 campaign reported episodes of sexual harassment, demeaning treatment, and pay disparity.

He said: 'It appears as part of our campaign there were some women who were harassed or mistreated. And I thank them from the bottom of my heart for speaking out. What they experienced was absolutely unacceptable and certainly not what a progressive campaign or any campaign should be about.

'The allegations that I have heard, that you have heard, speak to unacceptable behavior, that must not be tolerated in any campaign or in any workplace in our country.

'To the women in our campaign who were harassed or mistreated, I apologize. Our standards, our procedures, our safeguards were clearly inadequate.'

DailyMail.com has contacted Sanders' office for comment.