the U.S. Treasury has not taken the $50 billion of TARP money it is not using for housing--and another $100 billion or so of TARP money--and said: "Here is the equity tranche for a U.S. government-backed infrastructure bank. Go out and build stuff!"?
Build stuff? What percent of government expenditures at the margin, become 'stuff'? With a deficit of $1.4 Trillion, spending approved but not yet spent is not like some untapped reserve.
Spending other people's money on other people has a really bad ROE, highlighted by the total indifference to important issues like how money is invested. I would love to be this guy's broker! Consider how hard it is to manage an infrastructure project of say, $10MM. To think that one can, top down, spend $50B and create value anywhere near $50B highlights a total indifference to incentives and a reliance on macro aggregates (C, I, G, M, v etc) that have proven as useful as Marxist conceptions of capital and labor: fun to talk about, but ultimately meaningless.