Alzheimer's drug research has been one of the toughest fields in R&D, claiming a host of clinical trial failures. And now it's becoming an issue in the race for the White House. Democratic candidate Hillary Clinton wants to spend $2 billion a year on R&D activities in Alzheimer's over the next 10 years as millions of patients and their families deal with the memory-stealing malady. That's more than double the current spending. Story (sub. req.)