Donald Trump presided over a celebration at the White House yesterday that he claims will “honour our great country”, after abruptly cancelling a gathering with the Super Bowl champion Philadelphia Eagles over the flap involving NFL players kneeling to protest police brutality and systemic racism.

Trump insisted that the Eagles “disagree with their president because he insists that they proudly stand for the national anthem”, an assertion that carries echoes of dissatisfaction with their failure to submit to his will as well as any anger over treatment of the flag.

Of course, as The Washington Post reports, no Eagles knelt in this manner, and the team privately conveyed to the White House that fewer players than expected would show up. Trump told the lie about kneeling Eagles to justify the cancellation in part because he expected low turnout, which he hates.

But let’s not let the true import of Trump’s action get subsumed by the usual lying and megalomania. His true message is that African-American dissenters protesting in the quest for racial equality — in a manner he claims to find offensive — have no place at a celebration of this country’s heritage over which he is presiding.

In his statement cancelling the event, Trump claimed that the Eagles do not want to place “hand on heart, in honour of our great men and women of the military”. Instead, he said, he will preside over “a different type of ceremony” that will “honour our great country” and “loudly and proudly play the national anthem”.

In other words, whether any Eagles ever knelt or not, Trump’s explicitly stated justification for uninviting them is that they did kneel to protest the national anthem. That this is a lie is beside the point. The justification he is offering is itself a deliberate statement, and a reprehensible one at that.

After all, what if some Eagles had knelt, as he claims? His argument is that in carrying out this act, they have disqualified themselves from attending a celebration of American national heritage at his White House.

That some of the players were not going to attend anyway is also beside the point. They declined only after Trump repeatedly attacked the mode of dissent practised by their colleagues as unpatriotic — indicating that celebrations of patriotism will be permitted only on his terms.

Indeed, with yesterday’s celebration, Trump fairly leapt at the opportunity to make that statement. The President underscored the point, adding that at the festivities, there will be “no escaping to locker rooms”.

Only those who engage in displays of patriotism on his stipulated terms are welcome at his celebration to “honour our great country”.

The “different type of ceremony” Trump presided over was one that “loudly and proudly” celebrated the national anthem on those terms — that is, one that unabashedly placed that conditional display of patriotism at its core.

One does not have to support the players’ particular expression of dissent to recognise that it draws on a long tradition of African-American protest that has slowly and painfully forced this country to increasingly make good on the “promissory note” alluded to by the Reverend Martin Luther King Jr.

Our leaders should be expected to honour this tradition, as Charles Cooke has noted, by treating it as an essential part of celebrating our full history.

When Barack Obama spoke at the 50th anniversary of the violence inflicted on civil rights marchers on the Edmund Pettus Bridge, he noted that the promissory note has still not been honoured to all Americans. “This nation’s racial history still casts its long shadow upon us,” said Obama, who added that “we know the march is not yet over”.

The players are kneeling to protest America’s failure to eliminate systemic racism — racist police violence and sentencing disparities, and other racial barriers to opportunity — in continuation of that tradition, and in continuation of that march.

Trump cannot explicitly attack African-Americans for agitating for racial equality. Instead, he draws on another tradition that has long existed in tandem with African-American protest — one that long cast the protesters as anti-American.

“During the 1950s and early 1960s, Southern politicians routinely denounced civil rights activists as the knowing or unknowing agents of an international communist plot,” historian Kevin Kruse, the author of a book about white backlash against civil rights, tells me. “Even activists and organisations we now canonise as wholly American — figures like Rosa Parks and Martin Luther King Jr, groups like the NAACP — were at the time repeatedly depicted as dangerous radicals.”

Trump goes through the motions of canonising those figures when it is called for. But his brand of white-identity politics continues that other tradition of race-baiting disparagement, by disavowing the links between today’s African-American dissent and the protest tradition from which it is descended.

Yesterday’s ceremony at the White House tacitly honoured the first of these traditions and, in presiding over it, Trump in effect shirked his responsibility as president to honour the second.

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant — what you might call “opinionated reporting” from the Left