This is a good start at referential comparison. However, for any true comparison, taxes must be stripped from the price as they tend to fluctuate and can give an artificiality to the sampling.
Only if you’re looking at base gasoline price. The prices state by state might change if they change their tax rates on gasoline over those years, but the price out of the consumer’s pocket would be more and not less for most states. Seldom do states lower taxes. So that would also be in Trump’s favor.