The death hadn't even been confirmed, the body not yet cold, before the comparisons were being made.

The passing of Michael Jackson reignited the occasional debate about the King of Pop and Elvis Presley, "The King" of rock 'n' roll.

In the hours after Jackson's passing last week, Canadian songbird Celine Dion claimed it felt "like when (President John) Kennedy died, when Elvis Presley died. We are not only talking about a talented person dying, it's an amazing loss."

The articles analyzing the similarities between Jackson and Presley have been ubiquitous and inevitable. Even Billboard magazine editorial director Bill Werde declared, "The world just lost the biggest pop star in history, no matter how you cut it."

But is there really a case to be made that Jackson's and Presley's places in the pantheon of popular culture were as similar as some suggest?

Certainly, parallels between the two do exist. Both were born poor and became massive music icons on a global scale (though Jackson may have the slight advantage there as Presley never performed outside of North America). Each sold hundreds of millions of records and reached unimaginable levels of fame and wealth before experiencing rapid personal and professional descents (and, of course, there's the matter of Presley's daughter, Lisa Marie, who was married briefly to Jackson in the mid-'90s).

"Like Elvis, Jackson unified black and white listeners, and made startlingly important, memorable and era-defining music," says writer and music historian Alanna Nash, author of several Elvis books, including a groundbreaking biography of Presley's manager, Col. Tom Parker. "Jackson was also a completely luminous performer -- you couldn't take your eyes off of him -- and part of it was because you sensed that this was an extraordinarily damaged boy-man, again, like Elvis, a Peter Pan, a puer aeternus" (Latin for "eternal boy").

But unlike Jackson -- whose gaudy sales figures and personal excesses defined him -- Presley's impact and lasting relevance were part of a larger cultural phenomenon.

"Elvis emerged at a point in history where our culture was ready to turn itself upside down," says Dr. John Bakke, a professor emeritus of the University of Memphis' Department of Communication, who staged the first scholarly conference on Presley in 1979. "From the Depression on to World War II and then into the Cold War, there was a real drive towards security. Elvis came along at just the time the first identifiable generation of teen-agers were about to substitute a drive for freedom for their parents' drive for security.