Nine out of ten times the first objection that people make to direct democracy is the possibility of ending up with demagogues whipping their fellow citizens up to all kinds of ridiculous things. "Look at Hitler," they say, which is interesting, because while Hitler never came in remote contact with direct democracy, he'd be something of a poster boy for how electoral systems can work in favour of demagogues. After all, before the Nazis sent all opposing intellectuals (and there were a lot of them) either to concentration camps or pouring out of Germany, they never managed to gain so much as 50% of the popular vote. Only after they managed to gain control of mass media did things get really crazy.
And that is one of the main differences between ancient Athenian society and society today -- mass media.
We have it, they didn't.
Back then, if you wanted to find something out, you had to either figure it out yourself or ask another Athenian. No TV, no radio, no newspapers, nada. It was impossible to ever tell anything to anyone without simultaneously giving them the chance to object or talk back to you. And as many an Athenian who took an active interest in politics could tell you -- it's bloody hard to keep up a narrative that way. Not that it kept them from trying, not that it kept them from at times succeeding, but the crucial words here are: at times. Nothing is perfect.
But a system of mass one-way communication which doesn't give its listeners a chance to object or set the agenda is pretty nearly perfect for a demagogue.
It doesn't much matter whether said demagogue is elected, the non-elected head of a media conglomerate, or Mr. Charismatic operating in a direct democracy. No matter how cynical and sophisticated you are, mass media still has an enormous influence on each and every one of our incredibly malleable brains. Don't believe me? Check any or all of the numerous studies on this point (1) and then start observing some basic things about yourself, such as what you talk about over dinner -- the items you saw on the news today or a topic that wasn't on the news and which you've never heard of? That's a silly question, isn't it? But then again, it isn't. Because someone somewhere in the world decided what was going to be on the news tonight and now you are talking about that topic and not about whatever it was they decided was not important enough to put on the news. It's not a conspiracy -- it's just arbitrary and influences not only what you think about, but how important you rate it to be. And this assumes you are the sort of person who watches the news and then actually discusses it. Most people aren't so reflective, choosing instead to swallow their infotainment whole. In such an environment, he who controls the soundbite reigns.
Thus, having a "representative democracy" unfortunately isn't sparing us the demagogue problem. In fact, many media conglomerates thrive on feeding their viewers a constant diet of lies, bread and games, a diet which nevertheless has decisive consequences for national decision-making. Successful demagoguery gave us the Iraq War and killed off Obama's healthcare and inheritance tax reforms. It's now hard at work in Europe justifying why financial reforms are "impossible" and why everyone but the elite will have to rivet their work ethic up and their life expectations down.
By comparison a direct democracy has one important advantage: when people are told that what they decide right now is what they are actually going to live by in the future, it has a sobering effect on most of them. Bread, games and conflicting demands tend to get ratcheted down as serious debate goes up. In other words, by not giving people responsibility, but instead relegating them to a passive role in politics, we're actually fuelling demagoguery. When your choice is between supporting leader A or leader B, both of whom have pretty similar "policies", why wouldn't you go for the one who's the best entertainment value for money? Or at least the one who tells you what you want to hear, no matter how unrealistic it is?
Would having a direct democracy get rid of the danger of demagoguery? No, it wouldn't. Not in a mass media society. It would mitigate it, but, in my view, not enough. On the other hand, the current unholy alliance between super-elite "opinionformers" and the distracted proletariat is as unsustainable today as it was in the Roman Republic. Less sustainable, in fact.
Thus the fear of demagoguery is a valid point, but actually has little bearing on whether or not the political system chosen is a direct democracy. The real issue is mass one-way media communication, and as long as that problem isn't dealt with, we won't ever be getting real people power.
(1) see, eg. Shanto Iyengar/Donald R. Kinder, News That Matters: Television and American Opinion, University of Chicago Press, 1989