In the classic movie “The Sting,” Paul Newman explains to Robert Redford that in the most sophisticated swindles, the victim never even figures out he’s been conned.

Well, America’s churches got swindled big time in 1954. They lost their freedom of speech and a significant part of their freedom of religion.

There are two separate scandals here. The first is that Lyndon Johnson surreptitiously snuck a provision into the tax code that requires the IRS to regulate the content of every pastor’s sermon in this free land, and to threaten the tax deductibility of donations to any church that lobbies or takes sides in elections.

The second scandal is the fact that the churches of America have allowed this blatantly unconstitutional government censorship to persist for 58 years. It’s the most sophisticated kind of sting. Our churches haven’t even recognized they’ve been had.

First, a word about churches in the public square. There’s a strong case that this nation wouldn’t even exist without political preaching by pastors. During the Revolution the British noticed that the real impetus for the rebellion was coming from the pastors of non-Church of England churches. The Brits dubbed those preachers “The Black Robed Regiment” — and burned down their churches.

Slavery never would have been abolished in this country, or in England, if churches hadn’t preached and lobbied against it. The Civil Rights movement was driven by the preaching and lobbying of pastors like Martin Luther King, Jr. and others.

But Lyndon Johnson, the Democratic minority leader in the Senate, stood up and offered a floor amendment to the Tax Code of 1954. He asked that “tax-exempt non-profits” be forbidden from campaigning against him and his Senate colleagues in future elections. That sounded just fine to those Senate colleagues, and they accepted his amendment on a voice vote.

There was no notice, no hearings, and no debate. Johnson never mentioned churches. Congress has never voted to impose content censorship on America’s churches. But the IRS immediately swept churches into Johnson’s amendment.

And then the mainline denominations acquiesced in their own censorship! They didn’t stand up and fight for their right and obligation to provide moral leadership in American self-government. That abdication has led to a dramatic decline in those churches’ membership and America’s culture since 1954.

Lyndon Johnson gave absolutely no explanation for his amendment then or ever. Groups that support it today claim the non-profit tax exemption is a subsidy that somehow wipes away the First Amendment rights of churches.

Really? Aren’t farmers subsidized, and welfare recipients? When did they lose their free speech?

And what about labor unions? Aren’t they “tax-exempt non-profits”? Do they lobby? Do they get involved in elections? Maybe just a little.

And who else still has free speech in this country? Why it’s flag burners, and pornographers, and your local tax-subsidized PBS stations! They’ve all got the full-Monty of free speech. But not churches. America’s churches have been swindled. And it’s long past time to put an end to it.

The Johnson Amendment is so flagrantly unconstitutional that it’s almost certain to be struck down as soon as it reaches the Supreme Court. But the IRS has maneuvered to keep the high court from ruling on pulpit censorship for 58 years.

Now a group of lawyers, The Alliance Defending Freedom, has organized a campaign to force a test case. For the last four years, pastors across America have banded together on Pulpit Freedom Sunday to speak out on elections one Sunday a year, and send their sermons to the IRS. Last year 539 pastors participated and the IRS blinked once again. This year’s PFS will be October 7. Every Pastor who believes his or her pulpit should be free from government censorship should sign up and participate at PulpitFreedom.org.

It sure won’t be hard to find crucial moral issues that need to be preached about in this election!

Ken Hagerty is policy vice president for Renewing American Leadership Action.