What is an example of satire in Huckleberry Finn?

Huckleberry Finn satirized much of the commonplace society mores of the pre-war South. For example, the Widow Douglas wouldn't let Huck smoke, but "she took snuff, too." He also satirized the racial bigotry commonplace at the time, and relations between rich people and poor people.

Huck Finn also criticizes the institution of formal religion (i.e. going to church). Guns are seen being brought to church during the feuding portion of the novel. Also, at the beginning of the novel, Huck questions praying, wondering why he should pray if he never gets what he asks for. Therefore, he views religion as a lie, and hates it.

One of the main reasons that Huck Finn was so successful and is even banned in many classrooms today is that it has absolutely nothing to do with The Adventures of Tom Sawyer. When the novel first came out, everyone who read and loved Tom Sawyer (mostly white people) were horrified. A black slave was being depicted as human. Even though Huck cruelly plays tricks on Jim at the start of the novel (which the white southerners read and believed as commonplace), he experiences a major transformation from racism passed down from generation to generation (also a major criticism of society-racist "innocent" children) to realizing that Jim is a good person, and is equal if not better than himself. White southerners gently became more and more aware of their cruelty towards people (not slaves, people), and therefore cast the book away.

Most schools ban the book now because of the offensive language. The "n-word" is used throughout the novel extensively. But this language just adds to the whole novel by portraying the true treatment of black slaves in the south during that era. Huck Finn is no doubt a piece of realism, and by using the true dialects of the south, he realistically portrays the cruelty and dehumanization of African slaves in the south, and attempts to wake racist southern America to reality.

Huck Finn is a lot more than a book about a boy and a raft - it is a bitter criticism (masked in satire) of a society that Twain detested. If you read it in your 20s you'll find it is a lot more than the book you had to read in school in 8th or 9th grade.
Some examples of satire in Huckleberry Finn are the racism, and the discrimination towards other races and political news.