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United States President Barack Obama delivers remarks after meeting with members of his national security team concerning ISIS at the Pentagon on July 6, 2015 in Arlington, Virginia. Getty Images

Donald Trump's increasingly controversial campaign took a new turn Wednesday night when he accused United States President Barack Obama of creating the Islamic State group.

Speaking in Fort Lauderdale, Florida, the Republican presidential nominee alleged Obama had so screwed up the American response to the extremist organization that he "made a bigger mess out of it." Then Trump went even further.

"In fact, in many respects, you know they honor president Obama. ISIS is honoring president Obama," CNN reported he said. "He is the founder of ISIS. He's the founder of ISIS, OK? He's the founder. He founded ISIS."

Trump later said he thought Democratic presidential nominee Hillary Clinton, who served as Obama's secretary of state from 2009 to 2013, was the cofounder of ISIS, which has killed an estimated 33,000 people in the past 13 years and coordinated a series of major terror attacks all over the world.

To be clear: No matter how you feel about politics, there has been no evidence to suggest that Obama literally created ISIS.

"I would say it's another unsupportable conspiracy theory," John Limbert, an international affairs professor and former State Department counterterrorism official, told Politifact last month when Trump floated the concept that the president supported Al Qaeda and ISIS. Politifact rated the claim to be a "Pants on Fire" lie.

ISIS's generally recognized creator was a Jordanian man named Abu Musab al-Zarqawi, who started a group named Al Qaeda in Iraq in 2004 after leaving prison. He pledged loyalty to Osama bin Laden and wanted "to foment a civil war" by targeting Shiite Muslims, "causing them to retaliate against Sunnis, who would then have no choice but to turn to jihadists for protection," PBS reported.

Zarqawi was killed in an airstrike in 2006, but his ideas had taken hold. His successor, Abu Ayub al-Masri, changed Zarqawi's organization's name to the Islamic State of Iraq later that year. Masri also put Abu Umar al-Baghdadi in charge. A raid left both men dead in 2010, and Abu Bakr al-Baghdadi, the current leader of ISIS, took over, according to Stanford University's Mapping Militant Organizations project.

While ISIS was forming overseas, Obama was busy campaigning for and eventually being elected to the presidency. In 2014, he announced the U.S. was putting together an anti-ISIS coalition to conduct airstrikes on the extremist group.

"Our objective is clear: We will degrade, and ultimately destroy, ISIL through a comprehensive and sustained counterterrorism strategy," Obama said at the time.

The Pentagon has said its airstrikes have taken out more than 20,000 ISIS supporters.