WASHINGTON - Under fire for calling the United States a nation of "whiners" about the economy, former Sen. Phil Gramm of Texas resigned Friday night as co-chairman of John McCain's presidential campaign.

"It is clear to me that Democrats want to attack me rather than debate Senator McCain on important economic issues facing the country," Gramm said in a statement released Friday evening. "That kind of distraction hurts not only Senator McCain's ability to present concrete programs to deal with the country's problems, it hurts the country. To end this distraction and get on with the real debate, I hereby step down as co-chair of the McCain campaign and join the growing number of rank-and-file McCain supporters."

Gramm a week ago said in an interview with the Washington Times that people wrongly think the country's in a recession, even though it's not. A recession generally is defined as two consecutive quarters of negative growth. The economy continues to grow, though anxiety has jumped with rising gas prices, the subprime mortgage crisis and a drop in stock values.

"You've heard of mental depression." Gramm said. "This is a mental recession." The country, he went on, has become "a nation of whiners."

True or not, the sharp edge to Gramm's comments contradicted the message of concern about the economy that McCain was trying to convey as he launched a campaign swing vowing to restore jobs and boost the economy.

McCain disavowed his old friend, saying Gramm "does not speak for me. I speak for me. I strongly disagree."

Gramm is a former economics professor at Texas A&M University, and former chairman of the Senate Banking Committee. He ran for the Republican presidential nomination in 1996 but failed to win a single primary.