[WASHINGTON] Hillary Clinton admonished Donald Trump on Thursday for claiming she and President Barack Obama were the founders of the Islamic State group, as the White House rivals also clashed on plans to improve the US economy.
"No, Barack Obama is not the founder of ISIS," Mrs Clinton tweeted as she accused her 2016 election rival of a "smear" against the president.
"Anyone willing to sink so low, so often should never be allowed to serve as our commander-in-chief."
The Republican nominee roiled the campaign late Wednesday by telling a rally in Florida that Obama "is the founder of ISIS". "And I would say, the co-founder would be crooked Hillary Clinton," Mr Trump added.
A furious Democratic National Committee on Thursday called on the real estate mogul to "apologize for his outrageous, unhinged and patently false suggestions".
Instead, amid a flare of renewed controversy less than three months before the November 8 election, Mr Trump doubled down, repeating to homebuilders in Miami Beach, Florida that Mr Obama and Mrs Clinton founded the violent extremist group.
"ISIS will hand her the most valuable player award," he said of Mrs Clinton, 68.
Her campaign issued a stern statement saying Mr Trump has "an aversion to the truth".
"This is another example of Donald Trump trash-talking the United States," Mrs Clinton senior policy advisor Jake Sullivan said in the statement.
Mr Trump was "echoing the talking points of (Russian President Vladimir) Putin and our adversaries to attack American leaders and American interests, while failing to offer any serious plans to confront terrorism or make this country more secure," he added.
While Mr Trump's remarks landed him in fresh controversy, they did manage to push another deeply divisive row - his remarks that could be interpreted as advocating gun violence against Mrs Clinton - out of the headlines.
Mr Trump has struggled to right his campaign following two weeks of stumbles, sliding poll numbers and rejection by a series of fellow Republicans.
He eyed a reset Monday by rolling out his economic policies. But then dozens of respected Republican national security experts announced their opposition to a Trump presidency.
The following day, Mr Trump caused alarm when he suggested "Second Amendment people" - Americans who support gun rights - could act against Mrs Clinton.
Republicans have long stated that the foreign policies of Mr Obama and his then-secretary of state Mrs Clinton share blame in helping create conditions that allowed IS to grow in Iraq and Syria.
IS was founded in 2013, months after Mrs Clinton left the State Department. It was born out of the terror group Al-Qaeda in Iraq that grew in strength in 2006 following Republican president George W Bush's decision to invade the country in 2003.
The group flourished with Mr Obama's withdrawal of US troops from Iraq in late 2011.
Republicans said Mr Obama was slow to recognise the threat when he said in 2014 that the Islamic State was a "JV" - junior varsity - team even though they gained ground in Syria and Iraq.
Mr Trump stood firm when asked by CNBC whether it was appropriate to say a sitting US president founded a jihadist group determined to kill Americans.
"Is there something wrong with saying that?" Mr Trump, 70, said.
"Are people complaining that I said he was the founder of ISIS?"
"All I do is tell the truth. I'm a truth-teller."
Mr Trump endured a barrage of recent criticism, particularly over the Second Amendment remarks, which Mrs Clinton said had "crossed the line". Family members of Democratic president John F Kennedy, shot to death in 1963, expressed revulsion over Mr Trump for voicing "the possibility of political assassination".
Relatives of Republican president Ronald Reagan, who was shot and wounded in 1981, and slain civil rights icon Martin Luther King Jr also condemned Mr Trump for his gun remarks.
Mrs Clinton meanwhile turned toward the economy, telling supporters in Michigan she will defend US interests against China and reject the proposed Trans-Pacific Partnership trade agreement if she is President.
She also attacked Mr Trump for his economic positions, saying he was peddling a "myth" that "he will stick it to the rich and powerful". "Don't believe it," she said.
"He would give trillions in tax cuts to big corporations, millionaires and Wall Street money managers," she added.
Mr Trump hit back, arguing in Miami Beach that Mrs Clinton will raise taxes dramatically.
"I'm going to cut taxes big league," Mr Trump said.
His campaign also predicted Mrs Clinton, who supported TPP during the negotiation process, would ultimately approve the pact.