Are you sitting down?

Of course you are. So … I’m about to say something positive about Sen. Ted Cruz, who has actually expressed a difference of opinion with Donald Trump, a fellow Republican candidate for president of the United States.

Trump’s offensive notion of establishing a registry for Muslims has come between the men.

The only thing about Cruz’s criticism — such as it is — that bothers me is that he qualified it by calling himself a “big fan” of Trump. He differs with him on the idea of keeping such an eagle eye on Muslims because of their faith.

Cruz said the “First Amendment protects religious liberty.”

That, folks, is the central reason why Trump’s idea is a non-starter.

Some critics have compared the idea of a religious registry — even for U.S. citizens — smacks of what Nazi Germany did to Jews living in that country prior to the outbreak of World War II. We all know where that effort led.

Trump has been trying to take back what he apparently told a reporter about whether he’d like to establish a data base to monitor Muslims. He said he didn’t say that precisely. The record, though, suggests he did when pressed by a reporter.

As the Texas Tribune reported: “I don’t know what Mr. Trump did or didn’t say,” Cruz told reporters after a town hall Friday afternoon in Harlan. “On the question of should the federal government keep a registry of any religious group? The answer’s of course not.”

So, there you have it. Cruz and Trump actually disagree on something.

From where I sit as I watch Cruz’s campaign for the presidency, that’s progress.