Alexei Navalny attacked Putin’s Big Lie. GOP senators should do the same to Trump’s at his impeachment trial. | Trudy Rubin

For anyone who doubts why it is vital to move forward with the Senate impeachment trial, take a look at what’s going on this week in a Moscow courtroom.

On the same day Democrats laid out their case against President Donald Trump’s effort to subvert the U.S. election, Russian opposition leader Alexei Navalny was sentenced to 2 ½ more years in prison on trumped-up charges — after the Kremlin failed to kill him with poison.

Both cases revolve around this question: Can a democracy exist if its leaders base their power on flat-out lies to the public about the most essential principles of governance? Conversely, can an autocracy survive if it allows those lies to be refuted, in public, with compelling video, that reveals to the public how they have been conned?

» READ MORE: Russian leader Navalny risks it all for democracy. Will GOP senators do the same? | Trudy Rubin

Call it the Big Lie challenge. If a leader can convince the bulk of his public that the Big Lie equals truth — in other words, that 2 + 2 = 5, in the language of George Orwell’s 1984 — then democracy is doomed.

The Big Lie challenge was on view this week in Moscow. It will be in full view at Trump’s trial in the U.S. Capitol next week.

First to Moscow. Vladimir Putin’s Big Lie claims that he, and only he, is capable of restoring Russian greatness after the Soviet Union was broken and robbed by Russian so-called oligarchs in the 1990s.

But the charismatic Navalny, along with his courageous team, constantly punctures Putin’s Big Lie narrative with vivid videos laying bare the corruption of Putin and his cronies. Virtually all national Russian media is state-controlled and bans Navalny, and he is also barred from running in elections. This limits his reach, especially among older Russians who mainly watch TV, but he gets his message out on YouTube.

While recuperating from his poisoning in Berlin, Navalny tricked one of his intelligence agent poisoners by phone into revealing how the Novichok nerve agent was smeared on his underwear, and the audio went viral. And, after his return to Moscow, Navalny’s team released a two-hour video (with English subtitles) on a sinfully luxurious palace built for Putin on Russia’s Black Sea coast. The video racked up over one million views (which forced Putin to deny he “owned” the palace), and I highly recommend that you watch it.

This anti-corruption message has won him youthful followers around the country, whom he has helped organize to vote against Putin’s party in local elections. Thousands of demonstrators turned out all over the country last weekend after he was jailed.

So Navalny’s real “crime” is not the faked charges thrown at him in court, but his puncturing of Putin’s Big Lie. That is no doubt why the Kremlin risked sending agents to kill him with an internationally banned chemical substance. Putin of course denies this, as he denies a string of previous poisonings of opponents.

But an unbowed Navalny told the court Tuesday that Putin would “go down in history as a poisoner. Now we’ll have Vladimir the Poisoner of Underpants.” Even if state TV ignores him, that truth will reach millions of Russians via the internet. However, Navalny’s supporters fear Putin may have him killed while he labors in a Siberian penal colony.

Compare Navalny’s unbridled courage with the cowardice on view in the Senate. The Russian activist knows he has a Sisyphean task in trying to chip away at Kremlin lies. Yet he also knows Russia can’t liberalize politically until the false Kremlin narrative is cracked.

In the United States, on the other hand, the former president of the United States is still promoting the Big Lie that the election was stolen, a lie that led to the Capitol insurrection on Jan. 6. He is reportedly urging his new defense team to make that case at his Senate trial, where all but five GOP senators appear ready to give this lie a pass.

In late December, a YouGov poll found that over 70% of Republicans still believed Trump got more votes than Joe Biden. Obviously, that fantasy is still fueled by Trump, along with GOP legislators and officials and far-right media that profit off of conspiracy theories.

This is not a problem from which America can “move on.” As Navalny knows, a “Big Lie” poisons the political system. If 30% to 40% of Americans remain convinced that Biden lost, that is fuel for continuing violence and paralysis of Congress, and the poisoning of any serious political debate.

» READ MORE: The violence and conspiracy theories Trump fueled will threaten America after he leaves | Trudy Rubin

So the video evidence of Trump’s mad election claims, and the violence they inspired, must be laid out to the national public. Middle Americans need to know the details of his plotting to thwart a peaceful election. Unlike Navalny’s videos, this compilation will be widely shown, perhaps even on Fox.

It will lay out visually how the former president duped, and still cons, tens of millions of followers as if he were a cult leader. Trump, to paraphrase Navalny, should go down in history as a “poisoner of democracy” for his attacks on a fair election.

Yet, this will be a trial for GOP senators as much as for Trump, and whether they want to go down in history as “poisoners of democracy” as well.

Please join my conversation on the global vaccine mess with Dr. Paul Offit on Friday, Feb. 5 at 11 a.m. www.inquirer.com/trudyevent