Donald Trump's latest war of the worlds has all the makings of a political PR stunt.

The potential Republican presidential candidate recently fired off an angry leter to Jerry Seinfeld after he cancelled an appearance at an upcoming benefit for The Eric Trump Foundation and the St. Jude Children's Research Hospital.

The comedian reportedly became uncomfortable after Trump's outspoken questioning of President Obama's American citizenship.

According to CNN, Seinfeld's manager said he “feels this kind of demagoguery has no place in public discourse . . . He has respectfully withdrawn from the event, and is making a contribution both to the Eric Trump Foundation and to [St. Jude]."

Trump writes, "I just learned you cancelled a show for my son's charity because of the fact that I am being very aggressive with respect to President Obama, who is doing an absolutely terrible job as our leader -- just look at Libya, our economy, gas, food, and clothing prices and maybe you will understand what is going on!"

"We don't care that you broke your commitment even though the children of St. Jude are very disappointed, and despite the fact that your manager clearly stated you are 'truly a man of his word'," he added.

"What I do feel badly about is that I agreed to do, and did, your failed show, The Marriage Ref, even though I thought it was absolutely terrible... Despite its poor ratings, I didn't cancel on you like you cancelled on my son and St. Jude. I only wish I did. You should be ashamed of yourself!"

Trump neglects to mention in his letter that Seinfeld made contributions to both charities after his cancellation, but that was likely done on purpose to further demonize the comedian.

Musician Bret Michaels is set to appear in Seinfeld's place at the September event.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Trump blasts Seinfeld over charity cancellation
Business mogul fires off angry letter after comedian pulls out of an upcoming fundraiser.