The "further" relates to US Federal deficit spending, the idea being that +$1 trillion annual budget shortfalls will eventually trigger price inflation.

It isn't just Greenspan that is worried about rising US consumer price inflation; as we read through the most bearish market commentaries for 2020 this concern often has pride of place. Easy monetary and fiscal policy combined with a reaccelerating US/global economy late in a cycle is THE playbook for rising prices, so fair enough. The counterarguments are more structural (aging demographics, Internet price discovery, etc.), and while those work over the long term we can't lean on them too hard in any given year. So do the inflation hawks have a case to make about 2020?