House Democrats confident that their push for impeachment is a political slam-dunk might want to figure out how they can reconcile two contradictory facts.

On the one hand, they say that there is a clear case for impeachment that every voter can understand. On the other, Rep. Adam Schiff, who is leading the charge, is doing everything possible to keep the details surrounding the impeachment charge secret.

If impeachment is a sure thing, why hasn’t there been a vote on it yet?

If it’s so easy to understand, why is Schiff hiding key information about it from the public?

Asked Sunday on CBS’s Face the Nation about holding closed-door hearings with witnesses in the impeachment pursuit, Schiff all but admitted that the whole truth about the Democrats’ case isn’t really important.

“We want to make sure that we meet the needs of the investigation,” he said, “and not give the president or his legal minions the opportunity to tailor their testimony and in some cases fabricate testimony to suit their interests.”

In other words, Schiff doesn’t believe that Trump deserves the chance to confront his accusers — to respond to the full content of every secret hearing hosted by Schiff. Instead, Schiff believes the White House should only be allowed to respond to the selective bits that he and his Democrat colleagues decide to leak to the media.

Isn’t that exactly what you would do if you were confident that you had an unimpeachable case for impeachment?

“This has clarity and understanding in the eyes of the American people,” House Speaker Nancy Pelosi of California reportedly said in a private meeting with colleagues last month.

Rep. Debbie Dingell of Michigan, has said she believes that “everybody understands” the “very clear threat to national security and to our Constitution” that rose from the phone call.

New York Times' Charles Blow, master of original metaphors, has written this week that “the clarity” of Trump’s “transgression” on the call is “as clear as a bell.”

Eugene Robinson at the Washington Post has confidently declared that “it is not in question” that Trump “committed at least one impeachable offense” and that his “misconduct” is “easy to understand.”

If the case is so “easy to understand,” then when is the vote? Where are the articles of impeachment? Why is Schiff hiding the ball?

They won’t answer those questions. And the march to impeachment suddenly doesn’t look so hot.