Giuliani has been the subject of criticism since last week when he spoke at a private dinner for Wisconsin Gov. Scott Walker, a potential Republican presidential candidate.
"I know this is a horrible thing to say, but I do not believe that the president loves America," Giuliani said, according to Politico. "He doesn't love you. And he doesn't love me. He wasn't brought up the way you were brought up and I was brought up through love of this country."
The remark prompted a backlash, but in interviews in the days following the dinner, Giuliani didn't back down, saying his opinion was "perfectly reasonable."
Now he's seeking to explain himself further, but he also softened the message somewhat in the op-ed piece.
"My blunt language suggesting that the president doesn’t love America notwithstanding, I didn’t intend to question President Obama's motives or the content of his heart. My intended focus really was the effect his words and his actions have on the morale of the country, and how that effect may damage his performance," Giuliani wrote.
Obama lacking 'moral clarity'
He went on to say that Obama doesn't do a good job of defending American exceptionalism and that he too often criticizes his own country. Other presidents have been able to "walk a fine line" by putting their criticisms in the context of an "unbending belief in American exceptionalism," Giuliani argued, and Obama fails that balancing act, he suggested.
"And to say, as the president has, that American exceptionalism is no more exceptional than the exceptionalism of any other country in the world, does not suggest a becoming and endearing modesty, but rather a stark lack of moral clarity," the former mayor wrote.
Giuliani said he does believe Obama is "a patriot," that he bears him no ill will and that his personal story is inspiring but the positive words ended there. He implores Obama to start underscoring "America's greatness" and to "start acting and speaking in a way" that distinguishes the U.S. from its enemies.
Giuliani acknowledged that he has a reputation for being "blunt" and that he hopes what he says, whether people agree with him or not, prompts discussion about the country's future.