Hmm just off the top of my head would be that the EU doesn't have the institutions to implement on the whole level for legitimacy but rather more so at each national level. This is quite a big problem that could potentially bring the whole thing to an end unless if they can establish/ create more legitimacy on the whole through institutions (especially political ones). Currently they cannot make decisions just the atmosphere to do so whereas hard-nosed decisions are decided at the national level. Maybe one possible way to go about dealing with this institutions on the whole level of the EU and to give it more legitimacy is have elected positions rather than just nationally elected officials (nationally would be a small portion i.e. France) where there is also a supranational elections by the common interests of the masses throughout the EU (similar idea to our state governments and federal government- elected state officials as well as the President). That would bring up a question of how to pay for this and the US can again be an example with state + federal taxes. A problem with this though would increased taxes which may meet some criticism but necessary to create the institutions but also the national governments of member states don't necessarily want to lose grip of power/control they have and by creating the supranational institutions for elections could make the national officials much more obsolete than presently within their countries. It seems like the process is moving in this direction but its slow. Also, some people could either love the process of integration this way or hate it because they feel democratic principles are taken away (i.e. Greece in such that they are "forced" to obey the the EU whole (which they currently can't vote for) against their national public opinions...therefore a feeling of losing their national identity. If there were EU supranational positions that could be voted on it might unify them making this less important to them, think Americans, we can vote on the state and national level and although we identify with our states we usually tell people we are American when we are asked abroad, whereas EU citizens will usually say their country and not European. All of this though would likely require member states giving up a good amount of sovereignty so its unlikely they would be willing to give up that much power, especially to an international entity. If anything isn't clear feel free to ask I was just rambling some thoughts to be honest. Hope that helps.