ORLANDO, Fla. — After days of alleging repeatedly that President Barack Obama literally founded the Islamic State group, Donald Trump abruptly shifted tone on Friday and insisted his widely debunked claim had been sarcastic.

Trump, in an early-morning post on Twitter, blamed CNN for reporting “so seriously” that he had called Obama and Democrat Hillary Clinton the extremist group’s founder and most valuable player. He added, in all capital letters: “THEY DON’T GET SARCASM?”

Only hours before, the billionaire businessman had restated the allegation with no mention of sarcasm, telling rally-goers in Kissimmee, Florida, that “I’ve been saying that Barack Obama is the founder.” It’s a claim that Trump repeated at least a dozen times in three cities since debuting the attack-line Wednesday during a rally outside Fort Lauderdale.

In fact, Trump had refused to clarify that he was being rhetorical or sarcastic when asked about the remark during interviews. On Tuesday, when conservative radio host Hugh Hewitt tried to steer Trump toward explaining he really meant Obama’s Mideast policies created conditions that IS exploited, Trump wanted none of it.

“No, I meant he’s the founder of ISIS. I do,” Trump said, using another acronym for the extremist group. Told that Obama was trying to defeat the militants, Trump added, “I don’t care. He was the founder.”

The controversy over the Islamic State has dogged the campaign in a week in which he has been trying to highlight his economic proposals. Trump is encountering worrying signs as his campaign moves into the November election. Clinton’s lead over Trump in national polls has widened in recent days, while a growing number of fellow Republicans have declared they won’t support their own party’s nominee.

Clinton is looking to take advantage by expanding into traditionally Republican states, seeking a sweeping victory in November.

It wasn’t immediately clear why Trump altered course Friday and said the whole notion was sarcastic. But the allegation had elicited fresh concerns about Trump’s relationship with the truth and his preparedness to be commander in chief.

Clinton’s campaign has cried foul and accused Trump of mimicking Russian President Vladimir Putin’s talking points, and the Democratic Party had asked for an apology.

“I just do not think insults and bullying is how we are to get things done,” Clinton said as she laid out her economic plan Thursday in Warren, Michigan.