By the time the House impeachment managers finally wrapped their opening arguments Friday, it had become painfully clear that their goal in this trial is simply to spend as much national-TV time as they can get denouncing President Trump as a menace to the nation and the world.

It’s not about proving their case, or even making a real case for new witnesses and subpoenas; it’s not even about convincing “gettable” Republican senators to vote their way.

You can tell by the way the “prosecutors” keep showing their contempt for those Republicans, from Jerry Nadler’s charge the first night that they’re basically traitors if they don’t vote for more witnesses to Adam Schiff’s blaring Friday of the hearsay report that the White House is directly threatening GOP senators — a claim clearly proven false by those same senators’ live reactions of outrage.

And by the way Schiff and others have started bringing the whole “collusion” canard back into play — even though the Mueller investigation showed conclusively that there was never any collusion, and every senator knows it.

Not to mention the insult of the managers’ insistence on using all their available time to repeat the same basic points over and over and over again. It’s no wonder that senators from both parties have struggled to stay awake.

Indeed, that bald, incessant repetition is a clear sign of what the managers will offer if they do get to call new witnesses — more histrionics, more repetition, more delays. It’s as if the House members have been nursing jealous resentment of a senator’s right to filibuster, and are determined to do as much of it as they can while they’re visiting the Senate floor.

Sadly, you can expect Democratic senators to play along when they get to ask questions, by offering the managers more opportunities to say the same things yet again.

And never mind that the whole dog-and-pony show proves that the Democrats don’t even believe their own repeated claim President Trump poses such a clear threat to national security, and to the integrity of the November election, that he absolutely has to be removed from office at once. If they thought that, they’d never have had Speaker Nancy Pelosi sit on the articles of impeachment for four weeks, and they wouldn’t be wasting time now: They’d state the case once, and move on.

What’s the point of this “bore the jury when you’re not insulting it” strategy? Well, it stops the Senate from doing anything else — such as confirming more judges and other Trump appointees. And it lets the Democrats show their voters and donors that the politicians hate Trump as much as they do.

They may hope to also sway a few undecided voters, though we suspect this sorry spectacle is having the opposite effect. Indeed, Trump’s approval ratings are up significantly since this months-long fiasco began.

It’s not just the Senate that the managers are insulting with their games, it’s the whole country — and the country is noticing.

The Senate’s best answer is to vote as soon as possible to dismiss the House’s case, so Congress can get back to doing the people’s business.