The 'Bernie Blackout' is over.

Bernie Sanders, long overlooked in the Democratic race, is having a moment. In the polls, in the fundraising race and in high-profile spats with his 2020 rivals.

But one booster seems more surprising than most – Donald J Trump.

Lately Trump has tweeted about Sanders in ways that are sympathetic, if not totally supportive, of the Vermont senator.

"Wow! Crazy Bernie Sanders is surging in the polls, looking very good against his opponents in the Do Nothing Party" Trump wrote on 12 January.

The Democrat challengers to Trump in 2020 Show all 25 1 /25 The Democrat challengers to Trump in 2020 The Democrat challengers to Trump in 2020 Bernie Sanders The Vermont senator has launched a second bid for president after losing out to Hilary Clinton in the 2016 Democratic primaries. He is running on a similar platform of democratic socialist reform Getty The Democrat challengers to Trump in 2020 Joe Biden The former vice president recently faced scrutiny for inappropriate touching of women, but was thought to deal with the criticism well and has since maintained a front runner status in national polling EPA The Democrat challengers to Trump in 2020 Elizabeth Warren The Massachusetts senator is a progressive Democrat, and a major supporter of regulating Wall Street Reuters The Democrat challengers to Trump in 2020 Amy Klobuchar Klobuchar is a Minnesota senator who earned praise for her contribution to the Brett Kavanaugh hearings Getty The Democrat challengers to Trump in 2020 Michael Bloomberg Michael Bloomberg, a late addition to the 2020 race, announced his candidacy after months of speculation in November. He has launched a massive ad-buying campaign and issued an apology for the controversial "stop and frisk" programme that adversely impacted minority communities in New York City when he was mayor Getty Images The Democrat challengers to Trump in 2020 Tulsi Gabbard The Hawaii congresswoman announced her candidacy in January, but has faced tough questions on her past comments on LGBT+ rights and her stance on Syrian President Bashar al-Assad Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Pete Buttigieg The centrist Indiana mayor and war veteran would be the first openly LGBT+ president in American history Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Deval Patrick The former Massachusetts governor launched a late 2020 candidacy and received very little reception. With just a few short months until the first voters flock to the polls, the former governor is running as a centrist and believes he can unite the party's various voting blocs AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Beto O'Rourke The former Texas congressman formally launched his bid for the presidency in March. He ran on a progressive platform, stating that the US is driven by "gross differences in opportunity and outcome" AP The Democrat challengers to Trump in 2020 DROPPED OUT: Kamala Harris The former California attorney general was introduced to the national stage during Jeff Sessions’ testimony. She has endorsed Medicare-for-all and proposed a major tax-credit for the middle class AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Bill De Blasio The New York mayor announced his bid on 16 May 2019. He emerged in 2013 as a leading voice in the left wing of his party but struggled to build a national profile and has suffered a number of political setbacks in his time as mayor AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Steve Bullock The Montana governor announced his bid on 14 May. He stated "We need to defeat Donald Trump in 2020 and defeat the corrupt system that lets campaign money drown out the people's voice, so we can finally make good on the promise of a fair shot for everyone." He also highlighted the fact that he won the governor's seat in a red [Republican] state Reuters The Democrat challengers to Trump in 2020 DROPPED OUT: Cory Booker The New Jersey Senator has focused on restoring kindness and civility in American politics throughout his campaign, though he has failed to secure the same level of support and fundraising as several other senators running for the White House in 2020 Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Wayne Messam Mayor of the city of Miramar in the Miami metropolitan area, Wayne Messam said he intended to run on a progressive platform against the "broken" federal government. He favours gun regulations and was a signatory to a letter from some 400 mayors condemning President Trump's withdrawal from the Paris Climate Accord Vice News The Democrat challengers to Trump in 2020 DROPPED OUT: Kirsten Gillibrand The New York Senator formally announced her presidential bid in January, saying that “healthcare should be a right, not a privilege” Getty The Democrat challengers to Trump in 2020 DROPPED OUT: John Delaney The Maryland congressman was the first to launch his bid for presidency, making the announcement in 2017 AP The Democrat challengers to Trump in 2020 DROPPED OUT: Andrew Yang The entrepreneur announced his presidential candidacy by pledging that he would introduce a universal basic income of $1,000 a month to every American over the age of 18 Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Julian Castro The former San Antonio mayor announced his candidacy in January and said that his running has a “special meaning” for the Latino community in the US Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Marianne Williamson The author and spiritual adviser has announced her intention to run for president. She had previously run for congress as an independent in 2014 but was unsuccessful Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Eric Swalwell One of the younger candidates, Swalwell has served on multiple committees in the House of Representatives. He intended to make gun control central to his campaign but dropped out after his team said it was clear there was no path to victory Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Seth Moulton A Massachusetts congressman, Moulton is a former US soldier who is best known for trying to stop Nancy Pelosi from becoming speaker of the house. He dropped out of the race after not polling well in key states Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Jay Inslee Inslee has been governor of Washington since 2013. His bid was centred around climate change AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: John Hickenlooper The former governor of Colorado aimed to sell himself as an effective leader who was open to compromise, but failed to make a splash on the national stage Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Tim Ryan Ohio representative Tim Ryan ran on a campaign that hinged on his working class roots, though his messaging did not appear to resonate with voters Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Tom Steyer Democratic presidential hopeful billionaire and philanthropist Tom Steyer is a longtime Democratic donor AFP/Getty

A day later in a rally in Milwaukee the president weighed in on a testy row between Sanders and Senator Elizabeth Warren. He was quick to side with Bernie.

"[Ms Warren] said that Bernie said a woman can't win. I don't believe that Bernie said that," Mr Trump said. "I really don't. It's not the kind of a thing he'd say."

Democratic presidential candidate Sen. Bernie Sanders and Sen. Elizabeth Warren embrace after the Democratic Presidential Debate at the Fox Theatre on July 30 2019 in Detroit Michigan (Justin Sullivan/Getty Images)

But why is Trump suddenly so concerned about fairness? Does The President actually want Bernie on the rival ticket or is he trying to undermine the Sanders campaign with all this flattery?

After all, the polls may say Sanders would be the only candidate to beat Trump in a general election but the president's desire to railroad Joe Biden's campaign is now so well-known it got him impeached.

Indeed, Trump's fandom reached fever pitch when Hillary Clinton trashed Sanders in a stinging personal attack. Trump seemed personally affronted.

"When Hillary says nobody likes him, nobody likes her. That's why she lost.," Mr Trump said during an interview with Fox Business.

He later tweeted: "They are rigging the election again against Bernie Sanders, just like last time, only even more obviously. Very unfair, but that's the way the Democrats play the game."

Nomiki Konst, a political activist who worked as a national surrogate for Sanders in 2016, insists Trump is playing nice because he is running scared of Sanders' online support and he doesn't want Sanders to win.

"I think that – in private – Trump is scared of Bernie Sanders, partly because Sanders beats Trump in the polls," Konst said. "What Donald Trump isn't used to is Sanders' supporters and the real grass roots movement Bernie has. If Donald Trump signals he's ready to fight with Bernie Sanders, then the movement is going to start targeting Donald Trump. I think it's in Donald Trump's best interest to not pick fights with potentially the strongest democratic nominee in Sanders."

Others believe Trump's ploy is to use Bernie to further divide the indecisive Democratic Party

"I don't think it is meant to elevate Sanders," Josh Putnam, the political scientist behind DC company Frontloading HQ says.

"Instead, I think it is more likely that the president is attempting again to sow discord within the Democratic Party primary electorate, as well as the larger Democratic general election electorate.

"It is debatable just how effectively that sort of manoeuvering worked in 2016, but what's true is that Trump attempted to intervene and comment on the legitimacy of the 2016 Democratic nomination process and appears to be returning to that script for 2020."

Bernie Sanders responds to Hillary Clinton's 'nobody likes him' comments

Regardless of whether Mr Trump is trying to give an edge to Mr Sanders, one of his rivals, or simply trying to sow discord, Konst is sceptical of the president's influence over undecided Democratic primary voters.