1
general::
Phrase(s): (all) for someone or something
Fig. (completely) in favor of someone or something; supporting someone or something. • I’m all for your candidacy. • I’m for the incumbent in the upcoming election.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Completely in favor of something or someone, as in I'm all for eating before we leave, or The players are all for the new soccer coach. This colloquial phrase was first recorded in 1864.
American Heritage Idioms