This episode's headline: Gays in the Military; Democratic Debate; Revisiting Miranda; Old Story, New Music. ANCHOR: JIM LEHRER; GUESTS: MICHELLE BENECKE, Servicemembers Legal Defense Network; LT. GEN. PAUL CERJAN (Ret.), U.S. Army; LT. COL. ROBERT MAGINNIS (Ret.), The Family Research Council; MAJ. GEN. VANCE COLEMAN (Ret.), U.S. Army Reserve; BILL BRADLEY; AL GORE; FOCUS - REVISITING MIRANDA: PAUL CASSELL; STEVEN SHAPIRO; CORRESPONDENTS: PAUL SOLMAN; RAY SUAREZ; MARGARET WARNER; SUSAN DENTZER; GWEN IFILL; TERENCE SMITH; KWAME HOLMAN