Sunrise – Donald Trump accused President Barack Obama on Wednesday of founding the Islamic State group that is wreaking havoc from the Middle East to European cities. A moment later, on another topic, he referred to the US president by his full legal name: Barack Hussein Obama."In many respects, you know, they honour President Obama," Trump said during a raucous campaign rally outside Fort Lauderdale, Florida. "He is the founder of ISIS."He repeated the allegation three more times for emphasis.The Republican presidential nominee in the past has accused his Democrat opponent, Hillary Clinton, of founding the militant group. As he shifted the blame to Obama on Wednesday, he said "crooked Hillary Clinton" was actually the group's co-founder.Trump has long blamed Obama, and his former secretary of state Clinton, for pursuing Mideast policies that created a power vacuum in Iraq that was exploited by ISIS. He's sharply criticised Obama for announcing he would pull US troops out of Iraq, a decision that many Obama critics say created the kind of instability in which extremist groups like ISIS thrive.The White House declined to comment on Trump's accusation.Previous accusationsThe Islamic State group began as Iraq's local affiliate of al-Qaeda, the group that attacked the US on September 11, 2001.The group carried out massive attacks against Iraq's Shiite Muslim majority, fuelling tensions with al-Qaeda's central leadership. The local group's then-leader, Jordanian-born Abu Musab al-Zarqawi, was killed in 2006 in a US airstrike but is still seen as the Islamic State group's founder.Trump's accusation – and his use of the president's middle name, Hussein – echoed previous instances where he's questioned Obama's loyalties.In June, when a shooter who claimed allegiance to ISIS killed 49 people in an Orlando, Florida nightclub, Trump seemed to suggest Obama was sympathetic to the group when he said Obama "doesn't get it, or he gets it better than anybody understands".In the past, Trump has also falsely suggested Obama is Muslim or was born in Kenya, where Obama's father was from. The president, a Christian, was born in Hawaii.Trump lobbed the allegation midway through his rally at a sports arena, where riled-up supporters shouted obscenities about Clinton and joined in unison to shout "lock her up".He railed against the fact that the Orlando shooter's father, Seddique Mateen, was spotted in the crowd behind Clinton during a Monday rally in Florida, adding, "Of course he likes Hillary Clinton."Sitting behind Trump at his rally on Wednesday was former Republican Congressman Mark Foley of Florida, who resigned in 2006 after allegations that he sent sexually suggestive messages to former House pages.