You may have noticed an unusual amount of renewed attention being given to the Rosenbergs — that is, Julius and Ethel Rosenberg. That’s because there’s an aggressive push by liberals to try to exonerate the Rosenbergs, especially Ethel. This campaign has been going on for a while, but the hopeful are counting on one Barack Obama to come up big with a pardon for the two glorious comrades in these closing weeks of his presidency of fundamental transformation.

Julius and Ethel were the husband-and-wife team long ago convicted of treason and executed for atomic espionage — that is, for helping Stalin’s Soviet Union get the bomb. Sources as diverse J. Edgar Hoover and the Columbia Law Review would call it “the crime of the century.”

Predictably, the left judged the case a travesty of justice, a scandalous result of the “hysterical” anti-communism of the era.

Bunkum. Pure pabulum. Here are a few key facts:

As reported by scholars of the Venona papers and the Harvard Cold War International History project, Soviet espionage in the United States in the 1930s and 1940s was very extensive and successful. An estimated 350 Americans, including numerous high-level U.S. government officials and key scientists working on the Manhattan Project, were spying for Soviet intelligence. Beyond those was another group of helpers, a list of at least 200 more.

American officials were hardly acting hysterically; they fully understood the level of penetration that had occurred and its devastating effect.

The one group of Americans most oblivious to the very real threat of such people — including the Rosenbergs — was and remains liberals, especially the tenured radicals in our universities, who have long preferred to place America and American anti-communists in the dock rather than American communists. Ironically, the Soviet code name for Julius Rosenberg, found throughout the Venona transcripts, was one simple word: “Liberal.”

And the Soviets spoke to the great help of their Liberal friend. In fact, no less than Soviet leader Nikita Khrushchev himself testified to the Rosenbergs’ inestimable value: Khrushchev recalled overhearing Foreign Minister Molotov tell Stalin that “the Rosenbergs had vastly aided production of our atomic bomb.” Khrushchev said he learned that Julius and Ethel had “provided very significant help in accelerating the production of our atomic bomb.”

The Soviet leader was grateful to Julius and Ethel, and wanted to give them thanks. “Let this be a worthy tribute to the memory of those people,” Khrushchev asked. “Let my words serve as an expression of gratitude to those who sacrificed their lives to a great cause of the Soviet state at a time when the U.S. was using its advantage over our state to blackmail our state and undermine its proletarian cause.”

No doubt the Rosenbergs would have been inspired by similar lofty proletarian hopes.

To be sure, such inconvenient facts like these from Khrushchev have never deterred the left, particularly the sons of the Rosenbergs, who (naturally) went into academia, and who have fought tooth and nail every revelation asserting or proving their parents’ guilt.

But alas, in September 2009 came a final blow revealing the guilt of the Rosenbergs, one that even their children had to concede was devastating to their parents’ claims of innocence: Morton Sobell, the co-defendant in the historic espionage trial, came forward at age 91 and finally admitted that he and his friend, Julius, had both been Soviet agents — after he had insisted on their innocence for more than a half century.

Sobell’s concession left even the Rosenbergs’ children, Robert and Michael, with virtually nothing to say. “I don’t have any reason to doubt Morty,” Michael told the New York Times.

The revelation prompted Ron Radosh, the leading historian of the Rosenberg case, to once and for all write in the Los Angeles Times that the Rosenberg case was closed. They were Soviet spies.

Of course, they were. And that should be enough for even Barack Obama to just say no to demands for a pardon. We shall see.