During the rule of Pericles Athenian citizens were expected to be actively involved in the political decision making process?

Yes, the Assembly made all the decisions and the Council implemented them. Pericles therefore didn't rule, he had to persuade the Assembly to pass any proposals he made, and he didn't always succeed, even though he arranged the ostracism (banishment) of his chief opponent

Thucydides son of Olorus.