1
general::
Praise, promote, publicize, as in He's always beating the drum for his division, which actually has done very well. This term transfers the literal striking of a drum for ceremonial or other purposes to touting the virtues of a person, group, or product. [Mid-1900s]
American Heritage Idioms
2
general::
Phrase(s): beat the drum for someone or something [and] bang the drum for someone or something
Fig. to promote or support someone or something. (As if one were beating a drum to get attention.) • I spent a lot of time beating the drum for our plans for the future. • The senator is only banging the drum for his special interests.
McGrawhill's American Idioms And Phrasal Verbs