In case you don't know what Dog-whistle politics are, here is the Wikipedia entry description:
Dog-whistle politics is political messaging employing coded language that appears to mean one thing to the general population but has an additional, different or more specific resonance for a targeted subgroup.
The entry goes on to say:
The term can be distinguished from "code words" used in some specialist professions, in that dog-whistling is specific to the political realm. The messaging referred to as the dog-whistle has an understandable meaning for a general audience, rather than being incomprehensible.
It is that last sentence that makes dog-whistling so darn difficult to hear. The speaker is using words and phrases you agree with, but you may not be aware of the addition meaning(s) the speaker is communicating. So one is swept up in the speaker's language while potentially getting wrapped up in something you may disagree with.
Let me give an example here in the UMC.
Phrases such as "scriptural holiness" or "authority of scripture" or "I believe in the Bible" have become a dog-whistle in our denomination and you may no even know it. You and I read these phrases and say, well yes I agree with all of those statements. I also believe in those statements, however in many circles these statements are implying more than what is stated. Specifically, these statements are implying a "sola scriptura" theology. Again, I turn to Wikipedia to help clarify sola scriptura:
Christian theological doctrine which holds that the Christian Scriptures are the supreme authority in all matters of doctrine and practice. Sola scriptura does not deny that other authorities govern Christian life and devotion, but sees them all as subordinate to and corrected by the written word of God.
This may sound spot on for your theology and that is fine, however the United Methodist Church is not a sola scriptura tradition but a "prima scriptura" tradition. Take it away Wikipedia:
Christian doctrine that canonized scripture is "first" or "above all" other sources of divine revelation. Implicitly, this view acknowledges that, besides canonical scripture, there are other guides for what a believer should believe and how he should live, such as the created order, traditions, charismatic gifts,mystical insight, angelic visitations, conscience, common sense, the views of experts, the spirit of the times or something else. Prima scriptura suggests that ways of knowing or understanding God and his will that do not originate from canonized scripture are perhaps helpful in interpreting that scripture, but testable by the canon and correctable by it, if they seem to contradict the scriptures.
Finally, Wikipedia helps make the distinction:
Prima scriptura is sometimes contrasted to sola scriptura, which literally translates "by the scripture alone". Prima scriptura — is that the Scriptures are the sole infallible rule of faith and practice, but that the Scriptures' meaning can be mediated through many kinds of secondary authority, such as the ordinary teaching offices of the Church, antiquity, the councils of the Christian Church, reason, and experience.
However, sola scriptura rejects any original infallible authority other than the Bible. In this view, all secondary authority is derived from the authority of the Scriptures and is therefore subject to reform when compared to the teaching of the Bible.
Sola scriptura says, "scripture alone", prima scripture says, "scripture first." Sola scriptura is a zero-sum view of the world. That is to say, sola scriptura says that in order for the Bible to have the ultimate authority, all others much be diminished. Therefore, sola scriptura has less room for tradition, experience and reason than prima scriptura has.
Today, the phrase scriptural holiness is a bit of a dog whistle in the UMC by signaling to the listener sola scriptura theology.
Scriptural holiness is something that is more than likely something that most Christians affirm, however, it is worth asking the next question, "do you mean scripture first or only?"