See Synt. Laur. (cf. tau 435, introduction to notes), and Anecdota graeca (ed. Bekker, 1814/1965) 135.1. On the passive voice see LSJ, web address 1.
[1] For this sense of the verb for falling out or being banished cf. alpha 3324, delta 691.
[2] cf. alpha 3621, alpha 3591, alpha 4550, alpha 1493, eta 286, delta 691, tau 1147, etc.
[3] The Greek is tou= kalou= in the philosophical sense of the goal of human behaviour, the "good, honourable".
[4] cf. epsilon 3781, epsilon 2674, epsilon 2738, epsilon 2736, eta 647, kappa 1010. The text here is from Emperor Constantine VII Porphyrogenitus, rather than from Polybius; see further, next note.
[5] The quotation is related to Polybius 15.24.5, as in Constantine Porphyrogenitus, De Sententiis 171.7-17 (which it follows). The generalisation refers to the failure of newly established rulers to live up to their hopes or to those of their supporters. The text of the second clause in our Polybius mss reads in exactly the opposite sense: "on the other hand, they almost always do not fail in achieving their immediate self-interest" (tou= de\ parauta\ sumfe/rontos w(s e)pi/pan ou)k a)potugxa/nousi). The sentence in the Suda and Constantine makes for a better maxim or proverb, because of its paradox, and fits better with the following context. The text in the mss, however, applies only to the immedite result of coming to power (parauta/, cf. kappa 716), and leaves open the long-term consequences.