A single noun for a written article intended to persuade the reader to a particular political purpose?

Question

I know I've encountered this word before. Examples include almost every editorial and op-ed article.

It's not necessarily written, and it could be a speech.

The article doesn't necessarily persuade the audience, but the writer intends to persuade. It's more respectable and compelling than a screed. It doesn't have the pejorative shadings of propaganda, nor the semi-seriousness of public relations, nor the lofty pretension sometimes associated with eloquence and rhetoric, nor the aggressiveness of argument, nor the passionlessness of opinion.

Answer 1

A polemic is a a fiery proposition or editorial:

... an argument or controversy, especially over a doctrine or belief

Random House Kernerman Webster's College Dictionary

Answer 2

A position paper.

A position paper is an essay that presents an opinion about an issue – typically that of the author or some specified entity. Position papers are published in academia, in politics, in law and other domains. A position paper presents an arguable opinion about an issue. The goal of a position paper is to convince the audience that your opinion is valid and worth listening to. Ideas that you are considering need to be carefully examined in choosing a topic, developing your argument, and organizing your paper.

Position papers range from the simplest format of a letter to the editor through to the most complex in the form of an academic position paper.1 Position papers are also used by large organizations to make public the official beliefs and recommendations of the group.