Nothing resembles the ideological left quite so much as the ideological right; objectively, they are often political allies.

Both the doctrinaire left and the hardline right generally agree, for example, that there's far too much free speech nowadays; they differ only over who needs censoring.

What's more, both the left and right argue that bad people get far too soft a ride in the legal system.

The right would happily toss the constitution out the window to punish those it considers terrorists, and many on the left, judging from the trial of Jian Ghomeshi, think that due process — the steadfast application of evidentiary law — should be set aside in cases of sexual assault.

Every time Marie Henein, Ghomeshi's lawyer, produced another email or letter that contradicted, or, yes, showed a witness's previous testimony to have been false, social media swelled and roiled with loathing.

Henein was villainized, and those who defended her pitiless tactics were labelled rape-culture-denying, victim-blaming, pro-rapist, patriarchal, misogynist scum (I'm choosing the milder, more printable epithets here).

Those tweeting social media hashtags like #BelieveTheVictims basically argued that, once lodged, the sexual assault complaint itself should be the beginning and end of the judicial process.

The accomplished Canadian author Jane Eaton Hamilton made due process a gender issue: "Some men are up in arms this week, cautioning Canadian women to calm the (expletive) down. Don't get your sweet little heads all in a tizzy, they say, in Canada we have something called due process. This is supposed to happen to complainants in court. Ultimately, it protects all of us.

"We, the potentially violated … are saying This is not okay. This is an abridgement of Canadian values and Charter freedoms." (Her italics.)

Full disclosure

Neither Hamilton nor all the others who make more or less the same case have explained how exactly the Charter, which actually mandates due process, is somehow violated by due process.

Two prominent liberal columnists also suggested establishing special courts for sexual assault. That's not unreasonable, really, because sexual assault is already considered a special crime, with a special stigma.

There are, in fact, already special rules. Sexual assault is the one crime where the accuser (yes, even the false accuser) is allowed to accuse anonymously, while the accused, if an adult, is always publicly named.

Defence lawyers are also forbidden to explore the accuser's sexual history (something Heinen, it should be noted, did not do).

But the #BelieveTheVictim crowd seems to resent an accused's right to full disclosure of the Crown's case, and cross-examination itself.

University of Oregon students and staff demonstrate in May 2014, part of a wave of campus rape allegations in the U.S. that convinced the Obama administration to suggest more stringent, victim-rights rules for universities to adopt. (Associated Press)

They applaud the system adopted by many universities, particularly in the U.S., in which an administrative tribunal takes sexual assault testimony separately, and cross-examination is forbidden, on the grounds that it can re-traumatize someone; and the criterion for guilt is whether the offence likely happened, rather than reasonable doubt.

"It is absolutely remarkable," tweeted Toronto lawyer Alison Craig, "how many people seem to think that in cases of sexual assault, the guilty verdict should just be mailed in."

The Rolling Stone lesson

Craig says that criminal evidence must be tested for two things: credibility and reliability.

"Because we know that witnesses can lie, and witnesses can be mistaken. And the only way — the only way — their testimony can be tested is by cross-examination."

It's ugly, that bit about how witnesses lie, but some do.

I would bet that only a small corner of sexual assault accusations are false.

But when the full, terrifying power of the state is turned on you, and your accuser is telling lies, due process and the ability to test evidence is all that stand between you and prison.

My guess is the frat boys at the University of Virginia who were accused of gang rape in a Rolling Stone article were glad police decided not to automatically #BelieveTheVictim.

It turned out the anonymous accuser invented the whole episode.

Or the high school teacher in Fairfax, Va., accused of sexual assault by a 12-year-old student who later admitted she was seeking revenge for a scolding.

His professional and family life was ruined, but at least he is not in prison. Because the system did not automatically believe the accuser.

Or the three Duke University lacrosse players charged with rape by a lazy and incompetent district attorney. The accusation was later determined to be false, by testing the credibility of evidence.

In any event, to mock the notion that due process protects us all, as Jane Eaton Hamilton did, is intellectual self-indulgence.

Because, of course, it does protect us all. If any of Heinen's vicious detractors found themselves charged with a criminal offence, it's a safe bet they'd hire her, if they could, and hope she submitted the evidence to a severe credibility test.

I've quoted this before, but it remains to me the most eloquent defence of due process I've ever read.

It's a passage from A Man For All Seasons, in which the deeply principled Sir Thomas More is arguing with his fool of a son-in-law, Roper, about the need to prove guilt.

Roper: "So, now you give the Devil the benefit of law!"

More: "Yes! What would you do? Cut a great road through the law to get after the Devil?"

Roper: "I'd cut down every law in England to do that!"

More: "Oh? And when the last law was down, and the Devil turned 'round on you, where would you hide, Roper, the laws all being flat? This country is planted thick with laws, from coast to coast, Man's laws, not God's! And if you cut them down, and you're just the man to do it, do you really think you could stand upright in the winds that would blow then? Yes, I'd give the Devil benefit of law, for my own safety's sake!"

Just so.