Retweeting a New York Times piece which quoted Ralph Waldo Emerson – shortly after retweeting footage of a small-town mayor inadvertently live-broadcasting a visit to the toilet, thereby mixing low culture with high – Donald Trump seemed to confirm on Saturday that his campaign for re-election will be fuelled by “grievance, persecution and resentment”.

Quoting Times White House correspondent Peter Baker, Trump wrote: “Ralph Waldo Emerson seemed to foresee the lesson of the Senate Impeachment Trial of President Trump. ‘When you strike at the King, Emerson famously said, ‘you must kill him.’

“Mr Trump’s foes struck at him but did not take him down. A triumphant Mr Trump emerges from the biggest test of his presidency emboldened, ready to claim exoneration, and take his case of grievance, persecution and resentment to the campaign trail.”

Trump chose to pass his own comment only with a familiar claim about his impeachment and the Russia investigation before it, writing: “The Greatest Witch Hunt In American History!”

Baker’s piece was published on 1 February, four days before Trump’s acquittal in the third impeachment trial in US history. It was headlined: While stained in history, Trump will emerge from trial triumphant and unshackled.

Two weeks later, that prediction seems to have been born out.

Trump faced two articles of impeachment, concerning abuse of power in his attempts to have Ukraine investigate political rivals and obstruction of Congress in its own investigation of the matter.

The Republican-held Senate rejected attempts to hear testimony from witnesses and acquitted the president with only one GOP vote against, that of Mitt Romney of Utah, a longtime Trump opponent.

Since then, the president has called his impeachment “bullshit”; criticised Romney; fired a White House aide and an ambassador who gave testimony in the impeachment inquiry; and admitted sending Rudy Giuliani to Ukraine to dig up dirt on Joe and Hunter Biden, the matter at the heart of his impeachment which he previously denied.

Trump has also seemed to interfere in the sentencing of Roger Stone, his adviser who was convicted under special counsel Robert Mueller’s investigation of Russian election interference, links between Trump aides and Moscow and possible obstruction of justice by the president.

Stoking fears of a constitutional crisis, Trump has claimed the “absolute right” to interfere in justice department affairs.

Critics have said that indicates he thinks presidents are essentially kings, above the law, a view arguably reinforced by his attorney general although William Barr was moved this week to put at least tactical distance between himself and his raging president.

Emerson, a great American essayist of the 19th century, wrote his line about striking at kings when a pupil, the future supreme court justice Oliver Wendell Holmes, attempted to refute Plato.

Trump’s other early retweet on Saturday was of a message which said: “THIS IS HILARIOUS Mayor of Georgetown in the US excused himself to go & use the washroom in the middle of a meeting & forgot to switch off his mic on his tie & this is what happened.”

The event in question, replete with farting noises and giggling council members, happened in Georgetown, Texas in 2016. The mayor, Dale Ross, pronounced himself “not particularly embarrassed”.

Trump was in Florida, due to attend the Daytona 500 motor race on Sunday and act as grand marshal and starter in a play to his political base. It was reported that the president was planning a lap of the circuit in the Beast, his heavily armoured limousine.

Former White House spokesman Ari Fleischer indicated one motivation for attending the famous Daytona race, as his boss George W Bush did in 2004, another election year.

“There’s a real sense of positive, overwhelming affirmation to hear the roar of the crowd,” Fleischer told the Associated Press. “What politician doesn’t want that?

“Secondly, there’s what I call the reverberation effect. People watching at home, who hear the roar of the crowd for a president, that can drive them toward some sense of approval or fondness or liking for the president.”

On Saturday morning, Trump also repeated Fox News criticism of the decision not to pursue charges against Andrew McCabe, who the president fired as deputy director of the FBI in March 2018, two days before his scheduled retirement.