Rudy Giuliani doubles down on remarks about Obama's patriotism as biographer blasts him
Former New York City Mayor Rudy Giuliani (R) on 'The Kelly File' on Feb. 19, 2015 [YouTube]

Former New York City Mayor Rudy Giuliani (R) refused to apologize on at least two occasions on Thursday for his remarks questioning President Barack Obama's patriotism.

"I don't hear from him what I heard from Harry Truman, what I heard from Bill Clinton, what I heard from Jimmy Carter," Giuliani told Fox News host Megyn Kelly. "Which is these wonderful words about what a great country we are, what an exceptional country we are."

Later in the interview, Giuliani attacked Obama's grandfather for "introducing him to Frank Marshall Davis, who was a Commmunist."

"He fought in World War II," Kelly replied.

"You can fight in World War II, and then you introduce someone to a communist," Giuliani insisted.

"It's a political worldview," Kelly countered. "It's not a hatred for the country."

Giuliani's interview with Kelly came hours after he invoked the 9/11 attacks to criticize the president in a radio interview with Kelly's colleague, Sean Hannity.

"You know, President Obama didn't live through September 11 -- I did," Giuliani told Hannity. "President Obama didn't almost have a building fall on him. Myself and my police commissioner and my fire commissioner did. And, I lost 10 of my very close friends."

The former mayor and Republican presidential candidate has faced criticism of his own after his remarks at a dinner honoring Wisconsin Gov. Scott Walker (R) on Wednesday.

"I do not believe that the president loves America," Giuliani said at the event. "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."

Besides being ripped by liberal commentators, Giuliani was slammed by journalist and author Wayne Barrett in a column for the New York Daily News.

Barrett, who wrote a biography of Giuliani, called the mayor's remarks about Obama's parenting "a bow no doubt to the parenting prowess of Harold Giuliani, who did time in Sing Sing for holding up a Harlem milkman and was the bat-wielding enforcer for the loan-sharking operation run out of a Brooklyn bar owned by Rudy's uncle."

Harold Giuliani and five of his brothers, Barrett wrote, avoided serving in World War II, much like the ex-mayor received five deferments to avoid serving in Vietnam.

Barrett opened the piece by sarcastically observing that Giuliani "knows a lot about love."

"Ask Judi Nathan, his third wife, whom he started dating while still married to Hanover and New York mayor," he wrote. "In two SUVs, he and an entourage of six or seven cops traveled 11 times to Judi's Hamptons getaway at a taxpayer cost of $3,000 a trip. That's love."

Kelly's interview with Giuliani, as posted online on Thursday, can be seen below.