It's President Donald Trump's birthday.

On Friday, June 14, in honor of the Republican president's special day, thousands of people used a hashtag to troll him, and it quickly went viral.

It all started when an executive producer of "The Ellen DeGeneres Show" called on his followers to help Trump celebrate by making the hashtag #JohnMcCainDay a trending topic.

"Let’s celebrate @realDonaldTrump’s birthday today by having #JohnMcCainDay trend," Lassner tweeted. "I’m sure this would mean a lot to patriot like Donald Trump. #JohnMcCainDay"

Early Friday morning, the topic celebrating the late Arizona senator took off in the U.S. with more than 51,000 tweets using the hashtag.

'What the heck' is that? Security camera captures odd creature, and viewers have theories

Crop tops for men? Twitter users express mixed feelings about the new trend

Responses to Lassner's tweet varied.

Some criticized him for "playing childish games on social media," while others shared photos of McCain giving a thumbs up.

Canadian-American singer Kaya Jones writes: "You are a producer who makes a good living and has a mega job yet you spend your time playing childish games on social media with a sitting President."

Jones' tweet received 600 likes.

Some people used the hashtag to reflect on the Navy veteran's contributions to American history, sharing quotes and experts from books McCain wrote.

Twitter user Molly McKew shared a quote from McCain's memoir, "The Restless Wave."

"We were born to love, and we were born to have the courage for it. So be brave – the rest is easy," McKew tweeted. Twitter user Claude Call shared a quote from McCain that reads: "Our great power does not mean we can do whatever we want whenever we want, nor should we assume we have all the wisdom and knowledge necessary to succeed."

There's also a petition on Change.org to recognize June 14th as John McCain Day. The petition has over 500 signatures so far.

Trump hasn't shied away from criticizing the late senator, even after death.

In 2015, Trump explicitly argued that McCain was not a war hero because he was a prisoner of war in Vietnam for more than five years. McCain died in August 2018 following a battle with brain cancer.

In March 2019, Trump said he never liked the Arizona senator over differences that included Russia and health care. "I was never a fan of John McCain and I never will be,” Trump told reporters at the White House.

Follow Dalvin Brown on Twitter: @Dalvin_Brown.