WASHINGTON—Network news cameras covering Barack Obama's inauguration ceremony Tuesday captured Hillary Clinton silently moving her lips along with each word of the minute-long presidential oath of office. As she stood watching several yards from Chief Justice John Roberts, the former Democratic presidential candidate could be observed placing her left hand on a leather appointment book and raising her right hand slightly from her hip. Clinton, who carefully followed the swearing-in procedure with her eyes shut tightly, only varied from the president's words once, when she soundlessly mouthed her name instead of Barack Obama's. Clinton was later seen at an inaugural ball pretending she was dancing with first lady Michelle Obama.