Paul Schreiber blogs about the tech behind the websites of presidential candidates. "So, you want to run a country. Can you hire someone who can run a website? ...Here's how the (declared) candidates' sites fare." There's a table comparing 4 candidates' sites based on HTTPS, URL permutations, IPv6, SSL rating, and other related qualities. Schreiber mentions that he will "update this as more candidates declare or sites change."
From the blog comments
HillaryClinton.com was using IIS (and no https) until Sunday morning, when they switched over.
The same way you don't know that they broke into your house and replaced your laptop with one that will eat your children... The NSA is one of the few technically impressive pieces of the government left (just look at what NASA just let happen!). If they want your stuff bad enough, they will probably get at it. Although I do agree that HTTPS is a nice way to avoid being the low hanging fruit.