First from McCain, who first claimed that there was “strong evidence of a link between vaccines and autism” and now has since revised his position acknowledging that there is no scientific evidence supporting such a link and emphasized his support for autism research. See also Overlawyered, and here, and here. Obama has made similar references to the vaccine link and underlying science. More recently, Savage with a few dreadfully ignorant and attention-seeking claims (the link is to the NY Times post, not to Savage … here is an alternative link). Here is more on how the discredited theory has been kept alive.