An article in this month's edition of Vanity Fair suggests that former U.S. president Bill Clinton's volatile temper has hurt the White House aspirations of his wife, Hillary. (Elise Amendola/Associated Press)

Even as the U.S. presidential primary campaign comes to an end Tuesday, there's controversy swirling around former president Bill Clinton and his possible impact on his wife's run for the White House.

The ex-president has had to backtrack on harshly critical comments he made Monday night about a senior journalist for the magazine Vanity Fair.

In an article in the June edition of the magazine, staff writer Todd Purdum quotes a range of Bill Clinton's aides and confidants, some anonymous and some by name, who raise concerns about the former president's friends and business associates and say his jet-setting lifestyle and intemperate way of speaking have had a negative impact on spouse Hillary Clinton's faltering presidential campaign.

On Monday night, Clinton described Purdum as "a real dishonest reporter" and "sleazy." He said the Vanity Fair article had "five or six blatant lies in it" and was an attempt by the U.S. media to besmirch his wife while promoting her opponent, Barack Obama.

"It's all politics," Clinton said during a campaign stop in South Dakota. "It's all about the bias of the media for Obama.... This has been the most rigged coverage in modern history and [Purdum] ought to be ashamed of himself."

Purdum has told CNN that he stands by the article

Later the same day, Clinton's spokesman Jay Carson said the former president regretted his outburst but stood by his anger at the Vanity Fair article.

He "was understandably upset about an outrageously unfair article, but the language today was inappropriate and he wishes he had not used it," Carson said.

Mood swings after heart surgery: aides

In the 9,500-word magazine story, Purdum writes that some of Clinton's friends feel his personality and moods changed after he had open heart surgery in 2004.

"There's an anger in him that I find surprising," Purdum quotes one anonymous aide to the former president as saying. "There seems to be an abiding anger in him, and not just the summer thunderstorms of old."

Purdum says Clinton aides blame his intemperate criticisms of Obama, which some analysts have construed as deliberately stirring racist fears among poor whites, on the ex-prex's post-surgery mood shifts.

The article says Clinton's anger has hurt his wife's campaign for the Democratic presidential nomination.

"It has not served her well. That side of him feeds the worst side of Hillary," another anonymous aide is quoted as saying.

The Vanity Fair article also raises concerns about Clinton's business associates, including the Canadian mining magnate Frank Giustra.

The New York Times reported earlier this year that Clinton flew to Kazakhstan on Giustra's company jet. Two days later, the Times said, Giustra's company bought into uranium projects controlled by the Kazakh government.

It later emerged that Giustra was one of the largest backers of Clinton's charitible foundation, although both men have said the former president was unaware of the specifics of the Kazakhstan uranium deal.

The Vanity Fair article says the affair shows Clinton's political judgment may be faulty, even if his activities are perfectly legal.