You could call New Jersey Governor Chris Christie and Kentucky Senator Rand Paul members of the "vax generation."

Born in 1962 and 1963, respectively, they were in grade school when the newly developed measles vaccine became the life-saving advance that protected millions from a highly contagious childhood disease. Though not as scary as polio, it was potent enough to strike four million kids, hospitalize 48,000 of them with complications, and kill more than 400 every year.

That both men stoked an anti-vax movement this week by suggesting in the middle of a national measles outbreak that parents should be allowed to choose whether to vaccinate their children speaks to a generational shift in thinking about science and politics. Parents