Third Culture Kid (TCK) Barack Obama is best positioned to be George Washington to the world. He was born to a Kenyan in Hawaii, he grew up in Indonesia as a kid, he was America's first black president, and he did a decent job of steering America after a Great Depression like economic event. His Obamacare was so well placed, the opposition party, despite having all three branches of government at its disposal, has not been able to dislodge it, despite having opposed it non stop right from its enactment.
India leads on the biometric ID front. And Narendra Modi has acquired a Deng Xiaoping, Lee Kuan Yew like stature. Add to that India's population size and history of democracy, and that puts Modi in a strong place to help architect the world government.
The world government would be a new layer of government at the very top, just like the local level, the state level, the national level. It is the roof all national governments need.
One per cent of GDP should be the tax each national government ought to pay for membership. By the time the world government is put in place, the UN and all similar world bodies ought to be subsumed by the new world government. Take that World Bank, IMF, the International Criminal Court. Three branches make sense. You would not need a separate WTO, or G7, or G20.
New York City would be the legitimate capital, it still is the most diverse city on the planet.
You could have a bicameral legislature. In the lower house, each nation would have a voting weight in direct proportion to its population. In the upper house the voting weight would be in proportion to the size of the economy. At first the two houses would elect the President of the World. But soon enough perhaps the POW could be elected directly by people all over the world voting on their smartphones.
A world with a world government will have to become a borderless world. Maybe not as step one, but soon enough. How about the magic bullet with which to double the global GDP!