The world's most serious issues today are global ones: self-perpetuating violence, skyrocketing energy demand, environmental damage and economic dislocation. No single country, even the United States, can solve these issues single-handedly. While the US attempts to do just that, the European Union is taking the opposite approach--uniting. In fact, Maastricht has been so successful that a shocking 25 countries are member nations. The GDP of the EU is roughly equal to that of the US. Western Europe has the highest voter turnout on the globe.
If the current trend continues, the world will soon be organized around the EU, or its successor, and the US. Globalists in the states will push for US accession. Since the US Constitution, amazing at it is, does not contemplate its own demise, it will need to be amended rather than dissolved. That process will go to the states.
I see this bet as essentially describing the economic trajectory of the US. If the strength of the US economy is surpassed in a substantial way (probably through a major US industrial stumble) then the US would have to look to global government as a port in the storm.
I think Quigley is pointing out correctly that Icarus' wings are soft but I will argue that the weight of US military power will suffice carry the US constitution through 2025 without so much as a vote of consideration for a global authority.
The predictor will win if, by 11:59 pm (US Central Time) on December 31st, 2025, all U.S. states have voted on a constitutional amendment to cede some or all constitutional power to a global government. The challenger will win in all other cases. A global government is one that was formed through the combination of other previously sovereign nations. The outcome of the vote has no impact on the bet.