Here’s a great little term I’d never heard before, courtesy of the Double-Tongued Word Wrester Dictionary:

dog whistle politics n. a concealed, coded, or unstated idea, usually divisive or politically dangerous, nevertheless understood by the intended voters. Also dog whistle issue.

In a particular piece of serendipity, I came across it at roughly the same time as I found this post by Koby mentioning a few of the more charming things some Canadian politicians on the right have had to say about immigration over the years.