In February, Republicans were confident that gasoline prices would be a winning political issue in the fall. Commentators allied with the GOP predicted $5-a-gallon gas by Memorial Day and $6 per gallon by Election Day.

And they blamed the high prices on President Obama, saying it was a deliberate policy to drive Americans into using alternate forms of energy.

As they’ve proved in the past, gas prices are a thoroughly unreliable political issue.

They peaked in early April and have since fallen more than 50 cents to a national average of $3.40.

Indeed, falling gas prices are credited with holding down the consumer price index, the government’s basic measure of inflation. Consumer prices actually fell during the second quarter.

Each time politicians seize on gas prices as an issue, oil industry experts explain that prices are affected by a complex mix of factors – global demand, weather, refining capacity, civil unrest, underinvestment by state-owned monopolies and, most recently, Iran’s threats to shut off the Strait of Hormuz.

And, these experts point out, new energy projects can take years, even decades, to come online and begin affecting prices.

As good conservatives, Republicans are surely aware of economist Julian Simon’s famous bet with an ecological doomsayer that, over 10 years, rather than run out of certain commodities, rising prices would instead increase the world’s supply. Simon won the bet.

As always, when gas prices reach a level Americans feel they can live with, they lose interest in the issue and so do the politicians.