By Timothy Gardner WASHINGTON (Reuters) -U.S. President Joe Biden wants Congress to suspend the federal fuel tax for three months to help lower record gasoline prices that threaten some of his fellow Democrats who are candidates in the Nov. 8 congressional elections. Here are the main issues surrounding a fuel tax holiday: WHAT ARE THE FEDERAL FUEL TAXES? The federal fuel tax is 18.4 cents a gallon for gasoline and 24.4 cents a gallon for diesel, a level that hasn’t changed since 1993. At that time, gasoline cost about $1.05 per gallon, compared to just under $5.00 today, meaning it is a much …