When someone gets hurt by an uninsured driver, although the driver is at fault, the victim is left to foot the bill. Ultimately, the state governments and their law enforcement departments are responsible, and so they should bear the burden of paying for (the insurance for) the damages.
The federal government should require state governments to pay the damages when they let uninsured drivers on the road. Such a law would give state law enforcement agencies a clear economic incentive to enforce the law.