US President Donald Trump has taken an extraordinary action in his deepening feud with former President Barack Obama, refusing to unveil his predecessor's White House portrait.
It's a long tradition for the sitting President to invite the former Commander in Chief for the unveiling of his official portrait.
Sources close to Trump have told media that Trump's current campaign to investigate Obama means that any unveiling is impossible.
The same wasn't true when Obama held the top job. The 44th president said: "We may have our differences politically, but the presidency transcends those differences," when he unveiled George W. Bush's portrait in 2012.
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Author Kate Andersen Brower told CNN that the decision to not unveil the portrait charts a dark new course in US politics.
"Presidential portrait unveilings are one of the three events that bring former presidents together. This level of animosity between a sitting president and his predecessors is unprecedented in modern history," she said.
The startling development comes as Trump continues to push a narrative that Obama is involved in a "deep state" conspiracy that he has dubbed "Obamagate".
Trump has stated, without evidence, that he believes Obama had committed unspecified crimes, and some of his supporters have encouraged criminal inquiries into Obama and his vice-president Joe Biden for what they say are abuses during the investigation into ties between Russia and Trump's 2016 presidential campaign.
Trump has used his favourite medium to sell the theory, repeatedly tweeting what he has called "the biggest political crime and scandal in the history of the USA".
But Obama had a simple one-word response to the barrage of tweets.
Trump's efforts may not amount to any real-world consequences as Attorney General William Barr has signalled that he would not be swayed by political pressure to investigate the president's opponents.
- Additional reporting, AP