That's a common metaphor for the political process. I haven't been able to find out who coined the specific phrase, but the underlying idea goes back at least as far as John Milton's Areopagitica of 1644 and for modern political theorists is probably most associated with John Stuart Mill's On Liberty of 1859.
The basic idea is that if unrestrained speech and debate are allowed in the public sphere, truth and logic will ultimately win out because they have more inherent value than falsehood and irrationality. This idea was famously influential with the authors of the U.S. constitution and is the basis of the First Amendment.
I have always doubted this model of putatively democratic politics as a debating society. People are much too inclined to motivated reasoning and logical fallacies; and most do not have the informational background, methodological expertise or time and energy to distinguish truthful from tendentious claims. These problems are greatly compounded by the informational institutions that govern the public sphere -- precisely the so-called free press which is also protected by the First Amendment, but which inevitably promotes motivated points of view and includes irresponsible actors who promote falsehood.
At least it is possible, in principle, to respond to Fox News with reasoned presentation of facts and logic, although Fox News viewers aren't likely to hear you. The propaganda organs of the right no longer even try to make sense. Covid-19 is a hoax, the vaccines don't work, but Donald Trump doesn't get the credit he deserves for developing the vaccines -- presumably by himself in the White House basement, perhaps with the assistance of Steve Bannon. Now the new variant of concern is a liberal hoax that is somehow supposed to benefit Joe Biden politically and lead to a One World Communist state. But again, for all the good it will do me, I can respond to that with words of my own.
However, as The Nation's Jeet Heer tells us, for the right, it's no longer about ideas or arguments at all, even absurd ones. It's about violent threats and intimidation, without resort to thought at all.
The normalization of threats of political violence has been an intensifying trend in 2021. At its core is the simple fact that Republican leaders like [Sen. John] Barrasso have decided the party can’t afford to lose Trump—or even [Rep. Paul] Gosar. The GOP has become an alliance between the brutal and the craven.
Surveying the rise of threats of violence in public life, The New York Times reported on November 12 that “threats against members of Congress have jumped by 107 percent compared with the same period in 2020, according to the Capitol Police.” Remarkably, the situation is so bad that the paper, habitually given to framing all political disputes as the fault of both parties, was frank about the role of the GOP. The Times report noted, “From congressional offices to community meeting rooms, threats of violence are becoming commonplace among a significant segment of the Republican Party. Ten months after rioters attacked the United States Capitol on Jan. 6, and after four years of a president who often spoke in violent terms about his adversaries, right-wing Republicans are talking more openly and frequently about the use of force as justifiable in opposition to those who dislodged him from power.”
The howling mobs who show up at school board meetings threatening members aren't presenting arguments. They are trying to exercise power, for its own sake, by brute force. As Heer concludes:
Far from denouncing those issuing such threats, the GOP uses its political muscle to protect them. When the Justice Department indicated it was going to investigate threats to school board members over critical race theory, Republicans in Congress objected, with Representative Jim Jordan complaining of the creation of a “snitch line.”Ultimately, these threats of violence need to be understood as primarily a political problem. They are happening because the GOP views them as offering a political advantage with no real downside.
Try to find the Both Sides here. I dare you.
Update: Just what I expected. There is not one single Democratic elected official, in congress or state legislatures, or anywhere else that I know of, who endorses or condones violence. There may be some people who consider themselves leftists who commit property crimes, but even they don't threaten violence against public officials or invade capitol buildings. But in any case, they don't have anything to do with the Democratic party. If you can't understand that distinction, you couldn't find your own ass with a map and compass.
Read Jeet Heer's essay. He specifically names Republican elected officials who endorse and condone violence, including all but 2 Republican members of Congress and the former president of the United States.