https://www.vice.com/en_us/article/3ab4x9/just-how-bad-of-an-idea-is-a-gas-tax-holiday

On April 30, 2008, Urban Institute fellow Len Burman went on PBS Newshour to discuss the hot topic of the day: a gas tax holiday to ease the burden of soaring gas prices. It was a presidential election year and all the major candidates were involved in the debate. Senators Hillary Clinton and John McCain proposed a federal gas tax holiday, temporarily waiving the 18 cents per gallon federal tax, under the theory it would please voters and save them a few bucks at the pump. 

Senator Barack Obama was opposed on the grounds it would barely save people any money and only serve to pad oil company profits because they would simply take the 18 cents per gallon for themselves. He bolstered his argument by adding that as a state senator of Illinois in 2000, he had voted for a state gas tax holiday that got enacted, but it didn’t work.