I can't believe you fancy yourself a conservative and well informed enough to come on this forum, and don't understand this VERY BASIC AND NO DUH concept. Every dollar that does NOT have to go into energy costs will go into OTHER STIMULATIVE SPENDING by every consumer and every business in the country. Fuel is a huge line item for many industries, all those involving fleet management, but many more as well. When their fuel costs are lower, they can hire more, buy more newer vehicles, give raises, and invest other money into their businesses.
Meanwhile, consumers travel more, eat out more, shop more, and are more likely to upgrade their homes, etc. Astonishing, yes astonishing you don't see this. The relatively low cost of energy is one of the major advantages the USA has had for many decades. It's far more important than China's currency manipulation or almost anything else.
Here's one of millions of articles that you can find on the topic: http://www.pipelineandgasjournal.com/low-natural-gas-prices-create-jobs-spur-economic-growth-across-country