The first three are iambic tetrameters. The forth line has an extra syllable added to it using an unaccented "has" after the unaccented "er" in power making the syllable count nine instead of eight, with iambs before and behind "has." The rhymes are just two adjacent couplets.
Him still | must serve, | him still | obey,
And noth | ing act,| and noth | ing say,
But what | her haugh | ty lord | thinks fit,
Who with | the pow | er, has all | the wit.