Party caucuses, which date to the 1800s, have declined in importance but they could be decisive in choosing the 2008 Democratic presidential candidate.

James L. Jones, a retired Marine commandant, brings extensive military and diplomatic experience to his new post as national security adviser for President Barack Obama.

Retired Adm. Dennis C. Blair, President Obama’s director of national intelligence, is a former commander of the U.S. Pacific Command with long military experience.

Janet Napolitano, experienced in federal law enforcement and immigration issues, has been selected for secretary of the Department of Homeland Security.

President Barack Obama’s attorney general, Eric H. Holder Jr., has criticized some of the Bush administration’s counter-terrorism moves, calling for the closure of the Guantanamo Bay detention center…