When one assumes that the Chicago crew of economists are correct and that government must "fund" its spending with taxation or borrowing then the entire spending/bond/taxation relationship is distorted. The reason federal deficit spending increases GDP is quite simple. Its deficit is the private sector's surplus, and in aggregate comprises the "net" money supply after private sector debt is factored out.

It's hardly a shock that increasing the money supply by injecting at income levels prone to supporting velocity, as well as enabling net retirement of private bank debt, would boost GDP. Manchin isn't stupid. He, however, knows his constituency is econ illiterate and likely to adopt the simplest, and mostly wrong, theory of monetary expansion as the cause of erosion of the dollar's buying power. He understands that the best defense of his donors interests is simply to question how spending will be funded when it is the least relevant part of legislation.