Buying oil enriches countries antagonistic to the US. Iran, Saudi Arabia, Russia, Venezuela. Oil is a global commodity. If we use less oil then those countries will lose twice: Once because they're selling fewer barrels of oil and then again because, with less demand, pre-tax price per barrel goes down.
This also means we get free money at the expense of those countries. If we enter into a treaty with Europe and China to each put a $2/gallon tax on oil, that does not make gas go from $2 to $4, because the tax will reduce consumption (as intended), which reduces demand, which lowers prices. So instead of paying $2 of which $2 goes to the bad guys, you pay $3 of which $2 goes to Uncle Sam and $1 goes to the bad guys. Then that's $2 we can use to cut other taxes, $1 of which came from the bad guys. So not only is this revenue neutral, it's effectively a tax cut -- you pay $1 extra for gas and then pay $2 less in income tax. American taxpayers end up with more money in their pockets at the expense of Russia and Iran. And the higher we make the gas tax the more it reduces demand which transfers even more money from antagonistic foreign countries to US taxpayers.
Somebody tell me why CO2 even matters when carbon tax justifies itself regardless.