But The Arizonan was asking why Kennedy won a whole lot of other counties in Nevada, not just Clark.
It's actually only a relatively recent phenomenon that Mormons have tended to vote overwhelmingly Republican. Additionally as an historically stereotyped religious minority, Nevada Mormons were much more receptive to the Kennedy candidacy than many other populations within America.
Throw in the historic mining tradition in Nevada, add some extra dashes of rural ranchers feeling ok with LBJ as Veep, voila you have a wining combination....