No, I think civilized countries absolutely need a strong social safety net, and rich people should pay their fair share, but increasing spending before proving that you can get the rich to pay is putting the cart before the horse (and moves the burden to people who have don't have access to the tax avoidance techniques that the rich do)
I don't think you can make a social safety net dependent on your ability to make the rich pay their taxes. Both problems should be attacked in parallel.