川普称奥巴马是美国历史上最差的总统

U.S. Republican presidential nominee Donald Trump tweeted Tuesday that Barack Obama "will go down as perhaps the worst president in the history of the United States" after Obama called Trump "unfit" to lead.

"I think the Republican nominee is unfit to serve as president. I said that last week and he keeps on proving it," Obama said Tuesday at the White House.

But a former U.S. Marine attending a Trump rally Tuesday in Virginia told VOA he thinks Trump will be "a great commander-in-chief."

The outspoken Trump added another controversy to his growing list Tuesday when he accepted a Purple Heart medal from a retired lieutenant colonel before the rally in Ashburn, Virginia. Trump said the former soldier told him the gesture was intended to show confidence in him.

The Purple Heart is awarded to a U.S. serviceman or woman wounded in combat, or posthumously awarded to someone killed in battle. It is a sacred U.S. military tradition.

Trump, who says he regrets never serving in the military, said he was honored by the soldier's gift. The audience chuckled when he said he had "always wanted to get the Purple Heart. This was much easier."

But a spokesman for the Military Order of the Purple Heart organization, John Bircher, was not amused.

"It is absolutely horrible for anyone to wear or have the Purple Heart medal who is not entitled to it," Bircher told CBS News.

"Donald Trump did not get the Purple Heart and there's no 'easy way' to get it. I don't think he has any clue as to the meaning of the Purple Heart medal."