Sing From The Same Hymnbook Meaning

(idiomatic, of two or more people) To make the same or similar statements, especially to express the same opinions in public as a result of a prior agreement.

Example: 2002, Michael Wallace, "Greenspan Puts on a Happier Face," BusinessWeek, 25 Jan. (retrieved 12 Jan. 2009):
  Still, he mostly sang from the same hymnbook as the Bush Administration, saying fundamental fiscal trends are favorable.