THESAURUS
take sides
act with, align with, argue, argufy, back, back up, bandy words, bicker, cavil, champion, choplogic, contend, contest, cross swords, cut and thrust, discept, dispute, flock to, get behind, get in behind, get together with, give and take, go along with, go in with, hassle, have it out, join, join hands with, join issue, join up with, join with, line up with, lock horns, logomachize, moot, pettifog, plead, polemicize, polemize, quibble, rally round, range with, run interference for, second, side with, spar, stand back of, stand behind, stand by, stand in with, stick by, stick up for, strike in with, string along with, swing in with, take part with,
take sides with, team up with, thrash out, throw in with, try conclusions, unite with, wrangle