For public consumption, President Donald Trump planned to use his State of the Union address on Tuesday night to appeal for bipartisan unity. But at a private lunch for television anchors earlier in the day, he offered searing assessments of a host of Democrats.

Mr Trump dismissed former vice president Joe Biden as “dumb,” called Chuck Schumer of New York a “nasty son of a bitch” and mocked Governor Ralph Northam of Virginia for “choking like a dog” at a news conference where he tried to explain a racist yearbook photo, according to multiple people in the room.

The White House declined to comment on the president’s remarks.

Energised and blunt, Mr Trump held little back during the lunch at the White House to preview the State of the Union address. As he has in past years, he offered an unvarnished, unscripted view of the political world that went well beyond the heavily vetted speech he delivered to a joint session of congress and a national television audience.

He seemed confident about his chances for re-election next year, breaking down the emerging field of possible opponents with scathing assessments and predicting Democrats would move so far to the left that it would make it easier for him to win a second term.

Who could be running against Trump in 2020? Show all 23 1 /23 Who could be running against Trump in 2020? Who could be running against Trump in 2020? Joe Biden The former vice president - poised to be a frontrunner - has announced his run. He recently faced scrutiny for inappropriate touching of women, but was thought to deal with the criticism well AFP/Getty Who could be running against Trump in 2020? Bernie Sanders The 2016 runner-up has announced that he will be running again in 2020 Getty Who could be running against Trump in 2020? Hillary Clinton The 2016 Democratic presidential candidate and former Secretary of State says she is “still considering” whether she will run again. Getty Who could be running against Trump in 2020? Pete Buttigieg The Indiana mayor and war veteran will be running for president. If elected, he would be the first openly LGBT+ president in American history. Getty Who could be running against Trump in 2020? Kamala Harris The former California attorney general will be running for president in 2020. 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. AP Who could be running against Trump in 2020? Elizabeth Warren The Massachusetts Senator has formally launched her bid for president in 2020. A progressive Democrat, she is a major supporter of regulating Wall Street. AP Who could be running against Trump in 2020? Beto O’Rourke The former Texas congressman told Oprah Winfrey that he “has been thinking about running for presidency”, but stopped short of formally announcing his bid to run in 2020. AFP/Getty Who could be running against Trump in 2020? Wayne Messam Mayor of the city of Miramar in the Miami metropolitan area, Wayne Messam has announced his bid. He intends 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 Who could be running against Trump in 2020? Kirsten Gillibrand The New York Senator formally announced her presidential bid in January, saying that “healthcare should be a right, not a privilege.” Getty Who could be running against Trump in 2020? Cory Booker The New Jersey Senator has announced that he will be running for the presidency in 2020. If he secures the nomination he said finding a female vice president would be a priority. Getty Who could be running against Trump in 2020? John Delaney The Maryland congressman was the first to launch his bid for presidency, making the announcement in 2017. AP Who could be running against Trump in 2020? 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 Who could be running against Trump in 2020? Tulsi Gabbard The Hawaii congresswoman announced her candidacy in January, but is likely to face tough questions on her past comments on LGBT+ rights and her stance on Syrian President Bashar al-Assad. Getty Who could be running against Trump in 2020? Andrew Yang The entrepreneur has announced his presidential candidacy, and has pledged that he would introduce a universal basic income of $1,000 a month to every American over the age of 18. AFP/Getty Who could be running against Trump in 2020? Marianne Williamson The author and spiritual advisor has announced her intention to run for president. She had previously run for congress as an independent in 2014 but was unsuccessful. Getty Who could be running against Trump in 2020? John Kerry The former secretary of state has said he is still thinking about whether to run. Getty Who could be running against Trump in 2020? Michael Bloomberg The entrepreneur and former New York mayor– with a net worth of around $50bn – has said he will decide by the end of February whether to seek the presidency. AFP Who could be running against Trump in 2020? Howard Schultz Former Starbucks CEO Howard Schultz has not yet ruled out running for president in 2020, despite criticism that his bid could help re-elect Mr Trump by dividing the Democrat vote. AP Who could be running against Trump in 2020? Eric Holder The former attorney general has said he will decide in “the next month or so” whether to run as a 2020 presidential candidate. AP Who could be running against Trump in 2020? Eric Swalwell The California congressman said he is “ready to do this” and will decide before April whether to run. MSNBC Who could be running against Trump in 2020? Terry McAuliffe The former Virginia governor, who worked to elect Democratic governors during 2018 midterms, said there was a “50 per cent” chance he would run. AP Who could be running against Trump in 2020? Sherrod Brown The Ohio senator is still undecided about whether to run for president in 2020. Who could be running against Trump in 2020? Mitch Landrieu The former New Orleans mayor said he doesn’t think he will run for president, but “never say never”. AP Photo/Jacquelyn Martin

He said he hoped he would get to run against Mr Biden. “I hope it’s Biden,” Mr Trump said. “Biden was never very smart. He was a terrible student. His gaffes are unbelievable. When I say something that you might think is a gaffe, it’s on purpose; it’s not a gaffe. When Biden says something dumb, it’s because he’s dumb.”

He also expressed a desire to take on Elizabeth Warren of Massachusetts, whom he regularly derides with the racially inflammatory nickname of Pocahontas because she has claimed a distant Native American heritage.

“I hope I haven’t wounded Pocahontas too badly,” he said. “I’d like to run against her.”

Mr Trump said Kamala Harris of California has had the best campaign kick-off of any of the Democrats so far, a comment he also made in an interview with The New York Times last week.

But he dismissed Howard Schultz, the founder of Starbucks who is exploring a possible independent candidacy. “He doesn’t have a shot,” Mr Trump said. “Not a shot.”

As for the Democratic congressional leaders who have vexed him so much lately, he had kinder words for Speaker Nancy Pelosi of California than Mr Schumer. Ms Pelosi, he said, is nice to him in private but then says terrible things about him on camera. “Schumer,” he added, “can be a nasty son of a bitch”.

He also dismissed Mr Northam, the Virginia governor who is fending off calls to resign from Democrats and Republicans alike after the discovery of his 1984 medical school yearbook page that included a photograph of a man in blackface and another in a Ku Klux Klan robe.

Mr Northam initially confirmed he was one of the two men and then reversed himself at a Saturday news conference where he said he was not actually in the picture, although he had, on another occasion, worn blackface to impersonate Michael Jackson at a dance contest where he performed the singer’s famed moonwalk.

Mr Trump’s draft speech included a passage lashing out at Mr Northam for comments the governor made recently about late-term abortions. But at the lunch, the president also focused on the racial controversy, ridiculing his moonwalking comment.

“Did you see that news conference?” Mr Trump asked. “Could you believe it? He choked like a dog.”

Not every target was a Democrat. He recounted again the story of what he considered John McCain’s betrayal in voting against advancing a measure to repeal President Barack Obama’s health care program. Although McCain has since died, Mr Trump remains upset.

“By the way,” Mr Trump said, “he wrote a book and the book bombed.”