Gil Troy, a professor of history at McGill University, is the editor, with Arthur Schlesinger Jr. and Fred Israel, of “History of American Presidential Elections, 1789-2008,” fourth edition.

Mitt Romney’s apparent nomination proves that Republican voters are more pragmatic and centrist than their reputation suggests. The Republican candidates this year fought a classic political battle. Rick Santorum, Newt Gingrich and Ron Paul campaigned as purists, echoing Henry Clay’s famous expression from 1844, “I’d rather be right than president.” The realist Romney updated the belief of nineteenth-century partisans that a candidate’s most important ability is what they called his “availability,” as in “his ability to avail” – and prevail.

Gingrich and Santorum frequently justified their extremism by invoking the modern Republican demigod, Ronald Reagan. Gingrich is just now giving up on campaigning as a “Reagan conservative” against Romney, the “Massachusetts moderate.” In March, Santorum visited a Reaganite holy site – the Jelly Belly factory in Fairfield, Calif., which produced Reagan’s favorite jelly beans. “They’re asking you, people of principle, to compromise your principles and to be for someone who is less corely convicted than Ronald Reagan because we need to win,” Santorum said. He had a pragmatic argument too: “Every time we run someone that the moderate establishment of the Republican Party said we need to win, we lose.”

Santorum’s diction – corely convicted? – is as flawed as his historical memory. Republican voters have rejected culture wars and fanaticism in presidential campaigns repeatedly – they know culture warriors don’t win. Despite the talk about the rightward lurch of their party, a majority of Republicans have learned Reagan’s central political lesson. A Republican candidate can only win by wooing the center, and a president must govern as a national leader, not a factional chief or a cultural crusader....

Michael Auslin is a scholar at the American Enterprise Institute in Washington.

The Byzantine Empire’s long run — 1,100 years — may seem remote from the 21st century, but a reading of its history offers at least three timeless lessons. Understanding some of the fatal weaknesses in the Eastern Roman Empire may help clarify the political and economic problems that America faces today and the choices we have in responding to them.

Founded in 330 by the emperor Constantine, the eastern half of the Roman Empire was centered in Constantinople, the New Rome. By the fourth century, the empire had endured more than a century of instability, internecine warfare, and economic decline. In that context Rome’s eastern lands, arcing around Asia Minor, the Levant, and northern Africa, were especially attractive, being richer and more settled than the comparatively backward parts of western Europe. It was in part to assure continued access to these sources of wealth that Constantine relocated his capital. By A.D. 476, Rome had been overrun by barbarian tribes, and before long only Constantinople in the East had a seat for the emperors.

The first lesson for America to take from the history of Byzantium is about individualism and freedom. While it was no democracy, nonetheless Byzantium flourished when it allowed its citizens, and particularly its soldiers, greater individual freedom and responsibility. Beginning in the early 7th century, Emperor Heraclius moved from the traditional reliance on the provinces and their civilian governors and instead established large military zones, or “themes,” in Asia Minor, which was now the backbone of the empire. Centralization was maintained through the appointment of a single official with both civil and military responsibilities, but the real innovation of the themes was how the land was settled by imperial troops....

Jonathan Zimmerman teaches history at New York University and lives in Narberth. He is the author of “Small Wonder: The Little Red Schoolhouse in History and Memory” (Yale University Press). He can be reached at jlzimm@aol.com.

In 1979, 6-year-old Etan Patz disappeared on his way to school in New York. Last month, a fruitless search for Patz’s remains in a SoHo basement prompted a national wave of nostalgia for the innocent days of yore. For most of our history, we told ourselves, kids were safe. Then we lost Etan.

But we lost our innocence long before, with the 1874 kidnapping of 4-year-old Charley Ross right here in Philadelphia. That was when Americans discovered they could never keep their children completely safe. And we’ve been living with the consequences ever since....

Fifty years later, when Richard Loeb and Nathan Leopold were arrested for abducting and murdering 14-year-old Bobby Franks in Chicago, a member of their defense team reported that Loeb had been inspired by “a crime that nobody could ever detect” — the kidnapping of Charley Ross. Eight years after that, when the aviator Charles Lindbergh’s infant son was abducted and killed, one newspaper ran reward posters for Charles Lindbergh Jr. and Charley Ross side by side.

“The men and women who were children in the days of the Charley Ross kidnapping can remember how their mothers warned them to stay in the house, never talk to strangers, and regard every old clothes man as a potential ogre who would carry them off and strangle them and cut them into little pieces,” the New Republic editorialized in 1932, a few days after the Lindbergh baby was found dead. “The Lindbergh case is likely to produce an even wider reaction.”...