We shouldn't forget that the EU started off as a free trade agreement and a means of regulating the coal and steel industries, and 'would never' get to the point where an EU army or common tax policy were seriously considered. Yet here we are. What I'll say is inevitable is federal bodies gradually taking on more power for themselves at the expense of local governments. They may genuinely believe that it's for the greater good, or the leadership may just be frustrated with what they see as a pointless obstacle, but either way they're usually successful in turning the resources of the rest of the federation inward when met with resistance and the EU has been no exception.
You had fairly strong political support for a political federation ("united state of Europe") from day one. In some ways, it seems those ideas were more poular then than now, a Federal Europe was very much in the post-war
Zeitgeist. I mean, even during the War there was an official proposal to merge France and the UK into a single country. In addition, the "ever closer union" has been a thing since the
1983 Solemn Declaration of the European Union, 10 years even before the Single Market. Pretending the political union was snuck in is historical revisionism.
Now, to make things clearer to our Americans reader, we actually have something approaching a "Upper House" in the European Council (not to be mixed with the Council of the European Union, or worse, the Council of Europe. Isn't Europe fun? :p ). The European Council is made of the relevant minister from each of the government (so if it's an agricultural rule, it'll be the agriculture ministers and so on) and they also vote on EU law. In addition, for a lot of matter (migration, EU taxation, new country joining the EU, EU citizenship and some others) the council vote need to be unanimous, so every country got a veto.
In addition to that, seats in the European Parliament are also skewed so that smaller states get a higher share than their population alone would warrant, with a mimum of 6 seats each (out of 750). So Malta acount for 0.8% of seats but 0.08% of the population, while Germany account for 15.97 percent of the population but 12.8% of seats. (The cutting point is between Poland (38 millions inhabitants) and Romania (19 millions inhabitant): the bigger six countries are underrepresented, the bottom 22 are overrepresented). Now, here I disagree with
Helgoland in that I think that when looking at the raw "number of votes per seat", he ignores other aspect of the power dynamic. Basically, no one is going to ignore the Germans, even if their vote is individually worth less than that of the Maltese. In that sense, the German electorate is more powerful than the number alone suggest. On the other hand, if seat were attributed proportionally, would EU party even bother to campaign in Malta?