This refers to politicians who prefer the facts that they want to be true to those that are true. He is also behind the idea of "wikiality", whereby a concept becomes true if enough people agree with it.
While Colbert intends to send up the absurdities of politics on the other side of the pond, his notions are equally applicable here in the UK, not least in the gap between rhetoric and reality on housing development.
First, we had premier Gordon Brown's demand for three million new homes by 2020. Given the expected dearth of built environment professionals over the next 15 years, this takes truthiness to new levels. But now we have Office for National Statistics projections suggesting that the UK's population could grow by almost 16 million by the middle of the century, while the National Housing and Planning Advice Unit claims that another 30,000 homes are needed annually above and beyond Brown's wish-list.
Before the planning system steps up to its usual role as scapegoat for this escalation, a number of observations should be made. Failures in immigration, welfare, employment and education policy are behind this incipient shambles. No attempt is being made to shape the way the country is heading and much of that is down to the lack of a national planning framework.
While these big numbers are certainly alarming, they cannot all be right. However, the underlying message is that things are going to get worse - though how much worse is still anyone's guess. Despite the uncertainty, the figures point to a return to the bad old days of predict and provide. The government seems to have forgotten why that approach was abandoned.
The best-resourced system would find it hard to deliver anything like the number of extra housing permissions required on the ground. Even if the administrative machinery were in full working order, any government would struggle to fulfil the level of development that the top-end figures imply. Any that tries will be voted out.