Donald Trump Jr
Donald Trump Jr speaks on the second day of the Republican National Convention in Cleveland, Ohio, U.S. July 19, 2016.REUTERS/Aaron P. Bernstein

Donald Trump Jr, the eldest son of Republican nominee Donald Trump, accused President Barack Obama of lifting a phrase off his RNC speech for his address in Philadelphia on Wednesday, 27 July. Both speeches contained the line "That's not the America I know."

"I'm honoured that POTUS would plagiarise a line from my speech last week. Where's the outrage? #DemsInPhilly," Trump Jr tweeted. The accusation follows criticisms thrown at Trump Jr's step-mother, Melania Trump, for plagiarising a significant portion of her speech at the RNC from First Lady Michelle Obama's 2008 convention address.

NBC News reported Trump Jr was technically correct that both he and the president used the same line at their respective conventions. However, it is a line that Obama, and other presidents in the past, have used in their speeches. Unlike Melania and Michelle's speeches, Trump Jr and Obama's speeches were radically different, NBC News pointed out.

In Cleveland, Trump Jr said:

There's so much work to do. We will not accept the current state of our country because it's too hard to change. That's not the America I know. We're going to unleash the creative spirit and energy of all Americans. We're going to make our schools the best in the world for every single American of every single ethnicity and background.

Meanwhile, in Philadelphia, the president said:

What we heard in Cleveland last week wasn't particularly Republican and it sure wasn't conservative. What we heard was a deeply pessimistic vision of a country where we turn against each other and turn away from the rest of the world. There were no serious solutions to pressing problems, just the fanning of resentment and blame and anger and hate. And that is not the America I know. The America I know is full of courage, and optimism, and ingenuity. The America I know is decent and generous.

NBC News noted the president has used the phrases "the America I know" and "not the America I know" several times in the past. Before Obama used the phrase, however, President George W Bush used it. According to The Washington Post, prior to either president saying the phrase, it was uttered by journalist Walter Cronkite in 1998, civil rights activist Julian Bond in 1995 and by President George HW Bush in 1992.

Before them? It appears that David Westrate, of the Drug Enforcement Administration (DEA), used the line during a National Press Club speech in 1989.

Trump Jr later claimed he was not being serious with his accusation. "No, but I did think it was funny. The overreaction is even more funny," he wrote in response to a user asking him if he was being serious.