Homeland Security Secretary Janet Napolitano has ended the political speculation on whether she will leave President Barack Obama’s Cabinet to run for the U.S. Senate in the 2012 elections.

USA/Napolitano, a former governor from Arizona, told Democratic Party leaders earlier this week that she would not seek the open Senate seat.

“She cares deeply about Arizona, but the secretary intends to continue doing the job that the president asked her to do — protecting the American people from terrorism and other threats to our country,” her spokesman Sean Smith said in a statement on Friday.

Speculation about her possible candidacy emerged after the recent announcement by Arizona Republican Senator Jon Kyl, a three-term conservative, that he would not seek re-election.

It was not the first time during the two years that Napolitano has headed the Department of Homeland Security that rumors  swirled about her future. Napolitano’s name had cropped up as a possible candidate for a vacancy on the U.S. Supreme Court early in Obama’s  presidency.