And it's not just Trump, it's the whole Republican Party. You may remember how they exploited 9/11 in 2008 (and every year since the tragedy)
Driftglass gave this much historical context in 2009 (and you really should go read the whole thing):
After conspiring to bring about two of the most destructive events in modern American history -- the impeachment of a US President over trivia, and the probable theft of the subsequent Presidential election -- to what God could Republicans possibly pray that their eight years of insanity, venom and violence "might be wholly blotted out?”
On 09/11/01, their dark miracle came winging its way out of a clear, blue sky.
All of us, all together across all political, cultural and religious spectra watched the worst thing many of us had ever seen.
But in what now seems like less time than it took to wipe away our tears, the same depraved thugs who sponsored eight years of "Clinton Murdered Vince Foster!" hysteria began hijacking of our pain and patriotism to serve their partisan interests right before our eyes.
The minute the Bush Administration began trying to stretch the war they got into an excuse for the war they wanted, 9/11 stopped being merely a national tragedy and started being the Bush Administration's bottomless political ATM machine.
The minute the Party of Personal Responsibility began using the mantra "9/11 changed everything" as the political equivalent of the Blood of Christ -- as a means to absolve themselves of their personal responsibility for eight years of malice and derangement -- for them September 11, 2001 stopped being a moment of shared, national anguish and started being a suit of cultural body-armor which magically deflected any criticism of their lies and their hypocrisy.
An impervious sniper's nest from which they could cynically escalate --
"Conservatives saw the savagery of 9/11 in the attacks and prepared for war; liberals saw the savagery of the 9/11 attacks and wanted to prepare indictments and offer therapy and understanding for our attackers," Mr. Rove, the senior political adviser to President Bush, said at a fund-raiser in Midtown for the Conservative Party of New York State.
-- their war on the Left.
"Get Out of the 90s Free" card?
And the thing is, it worked.