GOP presidential nominee Donald Trump appeared to question the legitimacy of Barack Obama’s presidency once again on Saturday, referring to the president in air quotes.

Trump was speaking about Democratic rival Hillary Clinton’s proposal to allow more Syrian refugees into the United States when he made the comment during a rally in Bangor, Maine.

“She wants 550 percent more coming in from Syria than the thousands and thousands that our president, quote president, has coming in,” Trump said, making air quotes around the word “president.”

At Maine rally, @realDonaldTrump puts quote marks around "President" Obama. https://t.co/LSKIyG9EJC — ABC News Politics (@ABCPolitics) October 15, 2016

Of course, Trump first rose in politics by publicly questioning whether Obama was really born in the United States, which prompted the president to release his long-form birth certificate in 2011. Last month, Trump took credit for ending the birther controversy ― though he had done the exact opposite, helping to stoke it even after Obama initially released his birth certificate.

Trump also suggests Obama wasn’t his president during the first presidential debate, in which he referred to Obama as “your president.” Trump later clarified that he thinks Obama is “everybody’s president.”

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.