It does that because the congress decided to raid it starting in the Reagan years. We can end that by raising the ceiling to reflect what todays dollar is worth or take off the cap completely, cut the rate in half and it will be solvent for ever. It is where it is because only the middle class pays the bulk of it. Once you make more than 250K you stop paying into it. So it is a regressive tax structure that hits the poor and the middle class disproportionaly more.