That's not true. Humanity has taken steps backward before, and it can do so again. And if the United States and the west don't stay at the forefront of scientific research (the goal of these creationist lunatics), then other countries -- Korea and China, will be more than happy to take the lead.
Mankind is only becoming more informed, and the nation's sub-100s can do nothing about it. In our children's lifetimes, scientists will have perfected cell regeneration at the molecular level, thereby practically ensuring super-extended lives. They will look on us with pity.
Nothing the Cleti do will set back this advancement - best to make hay while the sun shines.