The gas tax isn't the only thing they are rioting over. They are also demanding a minimum wage increase, a cap on maximum wages, and they are demanding higher taxes for other things, just not gasoline.
So since he caved he must have worked out some other way to fund his social programs? Maybe a new vehicle excise tax so when all the people who had their cars destroyed buy new onces they can pay the bill? It's a nice way to royally screw someone 2x
Europe is a testing ground for the things the left wants in America. But their faith is never swayed when those things fail like carbon taxes, unchecked mass migration, healthcare that is rationed by time instead of money.