This blog at www.economist.com features the “Elizabeth Dole is Old” ad produced by the Democratic Senatorial Campaign Committee. It also poses a curious question:

If we travel down this road we may find ourselves atop the same slippery slope as the insurance industry. A number of scientific firms now offer tests to assess a person’s predisposition to specific ailments. So while the sound-minded Mr McCain might be more likely to suffer from dementia while in office, the younger Mr Obama might have troubling predispositions that we simply don’t know about. We require candidates to reveal their age when running for president, but if we are so concerned about the possibility of them falling sick in office, might we also require them to reveal their genomes?