Generally. This kind of democracy will always be prone to corruption by the rich and corporate elites, and it has become quite extreme in the 21st century. If anything this kind of corruption is worse on a national scale, afterall we can see that it exists in practically every country now, whereas in the EU there are conflicting interests amongst those elites, depending on what they have invested in and where. Either way the EU is rife with corruption, whether it's the MEP's who earn a lot for doing very little, or whoever it is that sponsors them.
Is there then, in your opinion, a solution? Direct democracy seems impractical with the sheer number of people involved in modern nation states.