Something in the media fury about Labour’s anti-Semites doesn’t add up.

We’re told that Jeremy Corbyn, being a stiff old radical and noted friend of Hamas, has helped to turn a once respectable party into a seething hotbed of Jew hatred. But the people being suspended from the party for having said dodgy things joined before Corbyn became leader. And they’re being thrown out by Corbyn.

The media narrative can be turned on its head: Corbyn could be seen, not as the importer of anti-Semitic thinking into Labour, but as the first Labour leader to take serious action against it. Perhaps he isn’t facilitating Labourite anti-Semitism but rather is doing something about it.

Whether it’s Ken Livingstone, who’s been in Labour since the Stone Age, or Naz Shah, who became an MP under Ed Miliband, these people ascended the party pole when Corbyn was just a scruffy Islington MP. Holding him responsible for their party membership or past comments is wrong.

It’s hard to dodge the feeling that some in the media, whether Tory columnists or Labourites hankering after the Blairite era, are using the anti-Semitism crisis to dent Corbyn’s leadership. This is a dangerous thing to do.

First, because it will make people even more cynical about the problem of anti-Semitism. Some will equate accusations of anti-Semitism with political point-scoring. And the last thing we need in this discussion is more doubt that anti-Semitism is a real problem.

Second, the narrow focus on Corbyn underestimates the depth of anti-Semitic thinking today. The modern left’s strange, heated obsession with Zionism, and its view of Zionism’s supporters as warped people unwelcome in polite society, has been growing for years.

It springs from the left’s abandonment of progressive thinking and its embrace of the conspiracy theory mindset, meaning it is always on the hunt for one evil force that might be held responsible for the world’s ills. Israel now plays that role, meaning leftists sometimes slip into an anti-Zionism that echoes the paranoia of the old anti-Semitism.

This is a long-brewing, profound problem. The Corbyn-bashers think they’re seriously tackling anti-Semitism when, in fact, they’re elevating their own urge to topple the Labour leader over the serious debate we need about the moral decay of the left and the return of an old prejudice.