There has never been a more limp climax in politics than with the Russia-collusion investigation. Yet Democrats, with great help from the national media, make us relive it over and over again.

The latest effort to resuscitate the very dead horse is the build-up leading to former special counsel Robert Mueller’s testimony in front of Congress this week.

CNN on Tuesday morning breathlessly covered a letter sent to Mueller by the Justice Department the previous day, which guides Mueller to only testify to the content of the 400-page report he released earlier this year.

CNN repeatedly called the letter a “warning” to Mueller from the Justice Department, once again setting Mueller up as the white knight in this endless nightmare.

“JUSTICE DEPT. WARNS MUELLER TO STAY IN ‘BOUNDARIES’ OF REPORT,” blared CNN’s on-screen graphic.

Even the Drudge Report linked to a story about the letter with the headline, “Justice Dept wants to stay on script…”

But the letter was nothing more than a reply to Mueller who himself asked the department for guidance on the parameters of his upcoming testimony.

The letter notes at the very top that Mueller requested “that the Department provide you with guidance concerning privilege or other legal bars applicable to potential testimony.”

The missive then goes on to recall that Mueller had already previously said in a public statement that any testimony he might be called on to provide would pertain only to his written report. It reminds Mueller there are court orders and regulations, though, that prevent him or anyone else connected with the special counsel office to discuss any ongoing legal matters and that it would violate department policy to discuss “the conduct of uncharged third-parties” (i.e. President Trump).

That’s not a “warning” no more than a “No Smoking” sign in a nursery is a “warning.” That’s doubly true considering it was Mueller who asked for the guidance.

All evidence suggests Mueller is offering his testimony reluctantly, having previously stated that he believed his written report on the Russia investigation thoroughly addressed any questions that Congress might have and that members were free to do with it as they wish. He even reminded them that they don't need him to start the impeachment process. Like Dorothy in The Wizard of Oz, Democrats have had that power all along right at their feet!

Mueller will probably say very little because he doesn’t want to say anything at all. Still, House Democrats will fish for a moment, any moment, that they can sell as a blessing for impeachment.

There’s no stopping that train, as we’ve seen over and over again, no matter how many times the effort to find collusion with Russia or obstruction of justice turns up empty-handed.

Don’t let the build-up over the “warning” to Mueller fool you. Mueller’s testimony will fall flat just like every other episode in this saga.