As the dollar continues to fall, the decline will tend to make gasoline more expensive (see Rick Newman's explanation why).
But regardless of the currency situation, Washington might make Americans pay more at the pump. The WSJ reports:
But skepticism remains high over whether any of the measures under consideration would spur significant job creation. Business executives are calling for more dramatic moves, including passage of a proposed six-year, $500 billion highway infrastructure bill, which some Democrats want to see funded through an increase in gasoline taxes.
Obama has come out in favor of a higher gas tax before. An effort to raise it before the midterm elections could give the GOP an opening against his party: Americans in the top 5 percent of the spending distribution tend to pay less of their household income on gas than the rest of the country, meaning one could argue that a gas tax increase is a middle-class tax increase.