Isn’t private capital the opposite of government spending?
Not when it starts out as government spending, sluicing wholesale into a gaping, capacious private-capital pocket.
We see this most frequently in military contracts, although NASA and public-works projects often oblige; most particularly nuke plants, of late. Public works and NASA innovate by sluicing to an impressively wide array of smaller yet still gaping pockets.
But that’s basically what is being praised as “investment” here.
The question is whether government spending is good, or whether we should let private capital fund it? (If private capital will fund it, but will then want to profit off of it.) The argument was that it would make sense to spend government money in that case.
"Fiscal responsibility" is just their smokescreen. They certainly understand the difference between spending and investment. They just want to own the investment part, while government does the spending part.