RUTHFULLY YOURS

America is experiencing a diversity and inclusion conundrum—which, in historical terms, has not necessarily been a good thing. Communities are tearing themselves apart over the statues of long-dead Confederate generals. Controversy rages over which slogan—“Black Lives Matter” or “All Lives Matter”—is truly racist. Antifa street thugs clash with white supremacists in a major American city. Americans argue over whether the USC equine mascot “Traveler” is racist, given the resemblance of the horse’s name to Robert E. Lee’s mount “Traveller.” Amid all this turmoil, we forget that diversity was always considered a liability in the history of nations—not an asset.

Ancient Greece’s numerous enemies eventually overran the 1,500 city-states because the Greeks were never able to sublimate their parochial, tribal, and ethnic differences to unify under a common Hellenism. The Balkans were always a lethal powder keg due to the region’s vastly different religions and ethnicities where East and West traditionally collided—from Roman and Byzantine times through the Ottoman imperial period to the bloody twentieth century. Such diversity often caused destructive conflicts of ethnic and religious hatred. Europe for centuries did not celebrate the religiously diverse mosaic of Catholic, Orthodox, and Protestant Christians, but instead tore itself apart in a half-millennium of killing and warring that continued into the late twentieth century in places like Northern Ireland.

In multiracial, multiethnic, and multi-religious societies—such as contemporary India or the Middle East—violence is the rule in the absence of unity. Even the common banner of a brutal communism could not force all the diverse religions and races of the Soviet Union to get along. Japan, meanwhile, does not admit many immigrants, while Germany has welcomed over a million, mostly young Muslim men from the war-torn Middle East. The result is that Japan is in many ways more stable than Germany, which is reeling over terrorist violence and the need for assimilation and integration of diverse newcomers with little desire to become fully German.

History offers only a few success stories when it comes to diversity. Rome, for one, managed to weld together millions of quite different Mediterranean, European, and African tribes and peoples through the shared ideas of Roman citizenship (civis Romanus sum) and equality under the law. That reality endured for some 500 years. The original Founders of the Roman Republic were a few hundred thousand Latin-speaking Italians; but the inheritors of their vision of Roman Republican law and constitutionalism were a diverse group of millions of people all over the Mediterranean.

History’s other positive example is the United States, which has proven one of the only truly diverse societies in history to remain fairly stable and unified—at least so far. Although the Founders are now caricatured as oppressive European white men, they were not tribal brutes. The natural evolution of their unique belief that all men are created equal is today’s diverse society, where different people have managed, until recently, to live together in relatively harmony and equality under the law.

Months of mounting frustration with the lack of progress in the Republican-led Congress drove President Donald Trump to cut legislative deals with top Democrats, according to White House officials, raising the prospect of future collaborations on subjects from immigration to a tax overhaul to spending bills.

In the past week, Mr. Trump has held two private sessions at the White House in which the Democratic congressional leaders walked away with either a deal or a path to one—largely on their own terms. Mr. Trump’s fellow Republicans were stunned by the shift from the president—whose chief interest is in jump-starting the stalled legislative agenda, say White House officials.

In one recent White House session, House Democratic leader Nancy Pelosi was listening to Treasury Secretary Steven Mnuchin beseech congressional leaders to raise the debt ceiling to steady U.S. markets, and the California Democrat grew impatient.

“Wall Street is one thing. You’re used to that world,” Mrs. Pelosi told Mr. Trump and Mr. Mnuchin. “Here the vote is the currency of the realm. It’s all about having the votes.”

In an interview Friday, Mrs. Pelosi said of the White House and Republican leaders: “They don’t have the votes.” She added: “Here we are in the minority…and we’re dealing from strength because they don’t have the votes.”

Mr. Trump has made clear that he is willing to use those Democratic votes to get legislation passed after splits in Republican ranks stymied his promise to repeal the Affordable Care Act, White House officials said.

In meetings, he has been apt to criticize legislative leaders, including Senate Majority Leader Mitch McConnell (R., Ky.), for taking a summer recess with so much unfinished business, and to complain of betrayals by GOP lawmakers whose votes he thought were locked in, White House aides said.

One senior White House official described an Oval Office meeting in which Mr. Trump said to him: “What’s wrong with you Republicans?” The official said of Mr. Trump: “Every time I’m in there, he’s like, ‘The Senate can’t get anything done. Why isn’t Mitch working? Why did they go home?’ ”

Mr. Trump now is courting Senate Democratic leader Chuck Schumer of New York and Mrs. Pelosi to see if he can propel tax, budget and immigration plans before Congress turns its attention to the 2018 midterm elections.

It’s unclear whether these new partnerships will endure. He once called Mr. Schumer a “clown” and Mrs. Pelosi “incompetent.” Still, “his No. 1 priority is to get the best deal: China, North Korea, Iran, Congress, Republican, Democrat—he’s about deals,” said Sean Spicer, former White House press secretary. “That’s it.”

Immigration has divided the Republican and Democratic parties a lot more than it has united them. That equation was scrambled this week when President Trump had dinner with Democratic leaders Chuck Schumer and Nancy Pelosi and emerged with the outlines of a deal on Dreamers. The WSJ’s Gerald F. Seib breaks down the odds of bipartisanship on immigration.

Two former top Obama-appointed prosecutors co-author a diatribe against Trump attorney general Jeff Sessions for returning the Justice Department to purportedly outdated, too “tough on crime” charging practices. Yawn. After eight years of Justice Department stewardship by Eric Holder and Loretta Lynch, and after Obama’s record 1,715 commutations that systematically undermined federal sentencing laws, we know the skewed storyline.

The surprise is to find such an argument in the pages of National Review Online. But there it was on Tuesday: “On Criminal Justice, Sessions Is Returning DOJ to the Failed Policies of the Past,” by Joyce Vance and Carter Stewart, formerly the United States attorneys for, respectively, the Northern District of Alabama and the Southern District of Ohio. Ms. Vance is now lecturing on criminal-justice reform at the University of Alabama School of Law and doing legal commentary at MSNBC. Mr. Stewart has moved on to the Draper Richards Kaplan Foundation, fresh from what it describes as his “leadership role at DOJ in addressing inequities in the criminal justice system,” focusing on “alternatives to incarceration,” and “reducing racial disparities in the federal system.”

The authors lament that Sessions has reinstituted guidelines requiring prosecutors “to charge the most serious offenses and ask for the lengthiest prison sentences.” This, the authors insist, is a “one-size-fits-all policy” that “doesn’t work.” It marks a return to the supposedly “ineffective and damaging criminal-justice policies that were imposed in 2003,” upsetting the “bipartisan consensus” for “criminal-justice reform” that has supposedly seized “today’s America.”

This is so wrongheaded, it’s tough to decide where to begin.

In reality, what Sessions has done is return the Justice Department to the traditional guidance articulated nearly four decades ago by President Carter’s highly regarded attorney general, Benjamin Civiletti (and memorialized in the U.S. Attorney’s Manual). It instructs prosecutors to charge the most serious, readily provable offense under the circumstances. Doesn’t work? This directive, in effect with little variation until the Obama years, is one of several factors that contributed to historic decreases in crime. When bad guys are prosecuted and incarcerated, they are not preying on our communities.

The thrust of the policy Sessions has revived is respect for the Constitution’s bedrock separation-of-powers principle. It requires faithful execution of laws enacted by Congress.

A concrete example makes the point. Congress has prescribed a minimum ten-year sentence for the offense of distributing at least five kilograms of cocaine (see section 841(b)(1)(A)(ii) of the federal narcotics laws). Let’s say a prosecutor is presented with solid evidence that a defendant sold seven kilograms of cocaine. The crime is readily provable. Nevertheless, the prosecutor follows the Obama deviation from traditional Justice Department policy, charging a much less serious offense: a distribution that does not specify an amount of cocaine — as if we were talking about a one-vial street sale. The purpose of this sleight of hand is to evade the controlling statute’s ten-year sentence, inviting the judge to impose little or no jail time.

That is not prosecutorial discretion. It is the prosecutor substituting his own judgment for Congress’s regarding the gravity of the offense. In effect, the prosecutor is decreeing law, not enforcing what is on the books — notwithstanding the wont of prosecutors to admonish that courts must honor Congress’s laws as written.