In an interview Tuesday, rock superstar Elton John told ABC News and Yahoo!'s Power Players that the American president who has done most to spread awareness about HIV is former Commander in Chief George W. Bush. John, a gay AIDS activist since the 1980s, previously described Bush as "the worst thing that ever happened to America" and criticized the president's policies in Iraq and Afghanistan. It's a turnaround that tracks the once-reviled president's comeback in the eyes of the public.

When Bush finished his second term in 2009 he left office with an approval rating of 22 percent. That number was one of the lowest in history as three out of four Americans did not approve of how Bush handled his eight years in office, according to CBS News. That number slowly started to turn around, though, and The Washington Post reported his approval rating had surged 30 points by the time he was set to release his memoir, "Decision Points" at the end of 2010.

Now, with his close aide Condoleezza Rice in the conversation as Mitt Romney's possible running mate and brother Jeb stumping for the GOP, Bush is no longer considered political poison as he was when John McCain struggled to distance himself from the then-president's unpopularity in the 2008 campaign.

On Tuesday, Elton John continued that trend. He cited Bush's President's Emergency Plan for AIDS Relief in 2004 for providing treatment and prevention awareness for Africans. PEPFAR was a $15 billion program, reports the Power Players. John admitted that meeting Bush at the Kennedy Center Honors in 2004 softened his view of Bush.

"I didn't like his policies but I have to say when I met him, I found him charming," John said. "I found him well informed and I found him determined to do something about the AIDS situation so I changed my opinion of him...I learned a lesson."

The Rock and Roll Hall-of-Famer also praised President Barack Obama for revoking the ban on entry into the United States by HIV-positive people, repealing "Don't Ask, Don't Tell" and endorsing gay marriage.

Elton John isn't the only liberal to rethink his stance on the former president. Debra Messing, once the star of television's "Will and Grace," has traditionally advocated for Democrats but she also voiced her support for Bush.

"President Bush created PEPFAR," Messing told Politico. "That's one of the most important contributions to this fight made by anybody, by any living president. So I think that regardless of his other policies, or how you feel about how he was as a president, anybody who is an advocate and trying to support global health has so much to thank the former President Bush for."

Since Obama took his seat in the Oval Office, Bush has avoided the spotlight. "Decision Points" has sold around 2.5 million copies and in 2010 he was making $150,000 per speaking engagement.

ABC News reported Tuesday Bush stopped by Romney's campaign office for a pep-talk and encouraged staffers "to seize the moment." But he recently announced he will not attend the Republican National Convention in Tampa. Former first lady Laura Bush said the couple is focusing on their AIDS work and is out of politics for good.