BUENOS AIRES, Argentina — The flamboyant wife of Argentina’s president, popularly known as “Queen Cristina,” yesterday launched a highly unusual campaign to succeed her husband as head of state.

Cristina Kirchner, whose husband, President Kirchner, has been in power since 2003, addressed her supporters in the Peronist Party in her home city of La Plata.

Credited with restoring Argentina’s economic health after the crisis of 2001, Mr. Kirchner would almost certainly have won a second term in office. However, in what could be a cunning move, he has decided to stand aside and allow his wife to run in October’s election.

“In Argentina, a president has never managed to maintain public support throughout two terms in office,” Olga Wornat, author of Mrs. Kirchner’s official biography, said.

“But sharing power with Cristina, letting her rule for the next four years, and then standing for re-election in 2011, will keep him popular, and potentially keep them both in power for 16 years.” The two view themselves as a joint political force, taking their cue from Senator and President Clinton.

The Kirchners met while studying law at university, and their political careers have moved in parallel for the past two decades. Mr. Kirchner was elected senator for Santa Cruz state — with Mrs. Kirchner as his deputy. And when he became president, Mrs. Kirchner swiftly took over her husband’s old senatorial role.

“The Kirchners did a lot for Santa Cruz,” said Fernando Palacio, the editor of El Santacruceño, a local newspaper there. “After Kirchner came into power, he created jobs and housing, and it became another world entirely.” If Mrs. Kirchner becomes president, she has pledged to continue her husband’s work.

“Take change further” is her slogan. And in a country where image is all-important, her similarities to an earlier national icon are likely to be crucial.

“The working class like her because she is living the dream,” Ms. Wornat said. “To them, she is the Evita Peron of the 21st century.”