There’s actually a little irony there. When taxes make up a small part the cost of fuel, a 50% change in the price of crude will push up pump prices by roughly that amount. However, for Europeans (who typically see a large, but consistent, part of the price of a litre going to their governments), the same rises and falls are hidden under the flattening effect of that fixed price.
Personally, I’d love to see a flat price dictated by government, with the taxes shrinking when petrol is cheap, and rising when it’s cheap. Given the volatility in crude prices since 2005 or so, that would have done a nice job in making the economics of recovery far more stable. (Lexington says that oil prices might not hurt the President directly ”unless they inflict much broader damage on the recovery”, but I’ve a suspicion that rising energy costs earlier in the recession helped stifle what ‘green shoots’ there were.)