Calderon fulfilled weeks of speculation by ousting Interior Minister Fernando Gomez Mont, the official most responsible for domestic security matters.

Gomez Mont's ministry oversees all police forces and is in charge of the government's offensive against powerful drug cartels — a strategy that Calderon has increasingly been forced to acknowledge is in need of adjustment. More than 23,000 people have been killed in 43 months, and drug trafficking organizations remain strong.

Yet Gomez Mont's resignation had more to do with electoral politics than security matters, Mexican analysts said.

He opposed the decision by Calderon's National Action Party, or PAN, to join left-wing parties in alliances for state and local elections July 4. As it turned out, the strategy proved successful, allowing the PAN-led alliances to win governorships in three states that had traditionally been controlled by Mexico's other main political force, the Institutional Revolutionary Party, or PRI. In fact, the PAN lost in every state where it ran alone.

Gomez Mont was burned in a mini-scandal in February when he appeared to be promising the PRI that the PAN would reject alliances, even as PAN officials were closing the deal. The episode embarrassed Calderon and undermined Gomez Mont's credibility while rendering him useless as an interlocutor with the political opposition. Gomez Mont resigned from the PAN, and some officials suggested then that it was just a matter of time before he would have to leave the government. He and Calderon have appeared estranged in recent weeks.

Gomez Mont had served in the post since taking over for Juan Camilo Mourino, who was killed in a plane crash Nov. 4, 2008.

Calderon, often criticized for placing personal friendship and loyalty over talent in filling his Cabinet, named Jose Francisco Blake Mora, from the PAN-dominated state of Baja California, to replace Gomez Mont. Blake, who is the state equivalent of the interior minister in Baja California, is a former federal legislator from that state and a close friend of Calderon.

Also quitting was Patricia Flores, head of the Office of the President, following reported frictions between her team and others in the presidency. She was replaced by Gerardo Ruiz Mateos, who until now had served as economy minister. Bruno Ferrari, who had been heading an agency dedicated to attracting foreign investment, was named to the post vacated by Ruiz Mateos.

Though the country is beset with violence and a sluggish economy, Calderon and his advisors are focused on 2012 presidential elections, in which the sitting president is constitutionally barred from being a candidate.

"All of these [Cabinet] adjustments," commentator Joaquin Lopez Doriga wrote this week, "are part of the relaunching of the Calderon government toward the final stretch of a fundamental decision: the formation of the PAN's presidential candidate."

wilkinson@latimes.com