If you have a front door, a Jehovah's Witness probably has knocked on it.
With well-dressed politeness and practiced persistence, they offer literature, biblical advice and a path to God's kingdom as they see it.
As often as not, they knock at the wrong time, when we're too busy to listen or not particularly interested in shopping for another faith.
But before you shut the door on a Jehovah's Witness the next time, pause to consider the shameful persecution they suffered not too long ago, as well as the rich contribution they have made to the First Amendment freedoms we all enjoy.
The legal clashes Jehovah's Witnesses had with government authorities over their proselytizing and practices led to an astonishing total of 23 separate Supreme Court rulings between 1938 and 1946 -- surely more than any other single religious organization engendered before or since. So frequently did Witnesses raise core First Amendment issues that Justice Harlan Fiske Stone wrote, ''The Jehovah's Witnesses ought to have an endowment in view of the aid which they give in solving the legal problems of civil liberties.''
Next month will mark the 60th anniversary of the most infamous Jehovah's Witness decision, one the Supreme Court got completely wrong: Minersville School District vs. Gobitis. The court, smitten by pre-World War II patriotic fervor, ruled it was constitutional to require Jehovah's Witness students to violate their faith and pledge allegiance to the flag in public school.
A Pennsylvania school district had expelled Lillian and William Gobitas (their last name was misspelled in court papers) because they kept their arms down during the daily flag salute. The Witnesses' interpretation of the Bible is that saluting the flag would amount to placing another deity before God.
As recounted in Shawn Francis Peters' powerful new book, Judging Jehovah's Witnesses, the Supreme Court's decision unleashed a wave of virulent anti-Jehovah's Witness persecution across the nation that is little remembered today.
Witness missionaries were chased and beaten by vigilantes in Texas. Their literature was confiscated and even burned. Less than a week after the court decision, a Kingdom Hall was stormed and torched in Kennebunk, Maine. American Legion posts harassed Witnesses nationwide. The American Civil Liberties Union reported to the Justice Department that nearly 1,500 Witnesses were physically attacked in more than 300 communities nationwide. One Southern sheriff told a reporter why Witnesses were being run out of town: ''They're traitors; the Supreme Court says so. Ain't you heard?''
Partly because of this violent reaction to its decision, the Supreme Court reversed itself with remarkable speed. On Flag Day of 1943, the court handed down West Virginia State Board of Education vs. Barnette, using some of the most eloquent language ever written to describe the First Amendment freedoms Americans enjoy. ''If there is any fixed star in our constitutional constellation, it is that no official, high or petty, can prescribe what shall be orthodox in politics, nationalism, religion or other matters of opinion,'' Justice Robert Jackson wrote.
The active persecution of Jehovah's Witnesses abated somewhat, although thousands were arrested during World War II for seeking religious exemption from military service. They were accused, baselessly, of being Nazi sympathizers. And Witnesses continued to have run-ins with the law over leafleting, in part because of their sometimes-confrontational style. Peters tells of a Jehovah's Witness caravan riding through Arkansas waving banners that read, ''Religion is a Racket'' and ''Preachers are Crooks.''
Today those messages probably would not cause a stir, and even then they should not have triggered violence. But in the America of the 1940s, they were pretty close to fighting words.
Speaking of ''fighting words,'' that concept was embodied in First Amendment law by another Jehovah's Witness case, Chaplinsky vs. New Hampshire. A Witness named Walter Chaplinsky was arrested in Rochester, N.H., for his fiery street-corner evangelizing, which included attacks on the ''harlot'' Catholic Church and on saluting the flag. The crowd that gathered became so angry that a man tried to impale Chaplinsky on a pole bearing the U.S. flag.
The Supreme Court's 1942 decision placed ''fighting words'' such as those used by Chaplinsky outside the First Amendment's protection if they ''by their very utterance, inflict injury or tend to incite an immediate breach of the peace.'' That standard remains relevant today and helped defeat politically correct speech codes that would have censored far-less harmful speech.
Perhaps the longest-lasting contribution the Witnesses made to First Amendment freedoms came in a 1940 case, Cantwell vs. Connecticut. The Supreme Court said Jehovah's Witnesses Newton Cantwell and his two sons, Jesse and Russell, should not have been arrested for soliciting without a license on the streets of New Haven, Conn. Before the Cantwell decision, it was not legally clear that the First Amendment protected religious practitioners against restrictions at the state and local levels as well as federal. But the Supreme Court in Cantwell said it did, thereby ushering in an era of greatly strengthened religious freedom.
All religions have the Jehovah's Witnesses to thank for the expansion of that freedom. But in their publications and on their Web site (www.watchtower.org) Witnesses make scant mention of their persecution and their legal battles.
Unlike other groups, the Witnesses have not resorted to televangelism and don't claim a high-profile presence in society. Witnesses -- all 1 million of them in this country, 3.5 million of them worldwide -- spread their message door-to-door and through the publications Watchtower and Awake!
''Their simple but eloquent voices tell a remarkable story,'' Peters says, ''one that lays bare the extremes of cowardice and courage so often found in nations engrossed in war.''
Tony Mauro, the Supreme Court correspondent for American Lawyer Media and a member of USA TODAY's board of contributors, is the author of a new book, Illustrated Great Decisions of the Supreme Court.