Only a limited one that promoted certain issues like medical care, human rights, infrastructure, democratization, economic growth, etc.
You run into tons of problems setting this up. In the US, in our senate we have 2 senators from each state. So Vermont has 2 senators and California has two, despite California having about 60x more people.
So does Morocco have as much of a say as China, and does a country like Myanmar or North Korea have the same level of influence as an established liberal democracy like France or New Zealand?
In the US, as a progressive liberal, I am pissed that I have to live under the leadership of senators elected in the south. There are 100 senators, and 26 come from the south. Of those 26, 19 are republicans. Of the remaining 74 non-southern senators a whopping 21 are republicans and of those republicans many are reasonably moderate (McCain, Luger, Snowe, Collins, etc). Extract the south from the equation and the US would’ve had labor and health reform a long time ago.
So I hate having to live with the consequences of decisions made by southern politicians in the US, and I’d hate having to live with the consequences of nations like China or Myanmar in a world government.
The human rights council in the UN has turned into a joke. The reason it did was because all the dictatorships got together and voted each other into leadership positions so they could avoid being criticized for their records. Now nations like Israel (which isn’t perfect but is still a liberal democracy despite all the threats it is under) is criticized far more than a nation like Libya, which despite being under fewer threats has a more oppressive domestic policy.
I do think everyone on earth is entitled to basic education, healthcare, infrastructure, human rights and civil rights. If a world government could promote those things (even if it meant overturning the decisions of sovereign nations), then have at it. The international criminal court as an example is something I can get behind, and I celebrated when they got 60 ratifications and it became a legit institution.
But I think a one world government should be limited to those things. And I think there is fairly broad consensus among the world that people are entitled to those things.And I would support global taxes to fund those programs.