"I'm all for taking it (infrastructure legislation) up once the president and Democrats, everybody says okay, here's how we're going to pay for it. As soon as that magically appears, I think we have a way forward," McConnell said. [Source]
Is he saying he doesn't know where money comes from? He knows. He just doesn't want to say it or use it.
Issue the money. Spend it right on infrastructure. That's all there is to it. The contractors and their employees will love it. They'll take their earnings and spend it back into the economy. The money will circulate. The GDP will go up, up, up. The public will love having better infrastructure. What's not to like?
Make the infrastructure green, and we'll have made the world a better place.