1. Keep the price of gas at the pump high enough so that people are willing and able to take public transportation and/or user alternatives to the one person per car commute.
2. Take that money from the tax and put it towards public transportation and alternative energy research and development.
Indirectly I think the gas tax would do a few additional things:
1. Get people to think about gas mileage when it comes to buying cars (which they don't do when gas is cheap).
2. Send less money to the countries that we buy oil from.
3. Keep people thinking about energy policy and national security every time they fill up at the pump.
I can think of a few arguments against the gas tax, and I have responses for them.
1. The government should not be trying to modify our behavior through taxes. My Response: This one is easy, the government already does this through crv taxes, federal income taxes, state income taxes, sales taxes, cigarette taxes, etc... The precedent for the gas tax has already been set.
2. There are struggling families out there that can't survive if we have a gas tax. My Response: This argument can be used against any existing tax, and the various government entities don't seem too concerned about it, so my lazy argument is that with all taxes, some people will come up just short.
The core problem, which is why we need a gas tax, is this: We, Americans, are very price driven people. When the prices of gas was high, we did change our driving habits, opting for less trips, more gas efficient vehicles, public transit, working from home, etc... But with gas prices going WAY down from their highs we are starting to forget about all that stuff. And I'm worried that we are going to go back to our big, bad, SUV driving ways. If you don't think that will happen, look at the 1973 oil crisis and the 1979 energy crisis. If we forget these lessons yet again we have no one to blame but ourselves.