Bret Devereaux

Importantly, people like Cleon and Alcibiades weren't presented as common people or following the will of common people; Thucydides saw them as cynical aristocrats, manipulating out of selfish, egotistic motives.

And being able to do so because, so long as the common people backed them, there was no ability for the rest of the elite to restrain them (contrast the Spartan gerusia or the Roman senate). Again, that's the line between democracy and oligarchy in Greece

Can 'the people' make policy decisions ("lets go with this guys plan!") on their own, or is there some mediating body of elites (often former magistrates or elders) who can pump the brakes if they think the people are being swindled?

If you have that sort of body of ex-magistrates or elders who *can* pump the breaks like that, you are at least talking about - in the ancient terminology - a mixed constitution, not a democracy.

But Pericles -- granting that, as written, he seems like a fantasy leader -- didn't have any constitutional power like that. He worked by persuading the voters (and delaying the assembly in one case cited.) Granting elites that power doesn't give you Pericles-grade leadership.

I guess I don't see anywhere Thucydides saying or implying "You know that good leadership you had with Pericles? Put the elites in charge, have that always!"

And while I hear what you're saying about direct democracy, during this conflict democratic parties and oligarchic parties were fighting to the death. They weren't killing each other over whether leaders led the people or were led by them. The differences were more gross.