It is just so far out in LEFT field that I had to say it.
Even if more U.S. drilling did not reduce gas prices as a matter of history - the principle behind it is as solid as anything gets.
Water IS wet. Summer IS warmer than winter. Gravity IS an attractive force. And an increased supply of something IS going to reduce the price.
It may not have brought down the actual price because of an ever increasing DEMAND - but an increased supply will ALWAYS reduce the price more than if there was NOT an increase in supply.