Then why not publish it as soon as Coakley entered the race? Or as soon as she won the Democratic primary? Why only do so after Brown's momentum was already readily apparent? It reeks of opportunism, particularly coming from the WSJ.
The WSJ is a national newspaper, not a Massachusetts newspaper. It reports on Massachusetts politics only when they are of national interest.
But yes, they presumably intended that piece to have a partisan impact in much the same way as the AP sat on the Bush DUI story until the weekend before the 2000 election. Difference being that, instead of
withholding relevant information until it could have maximum partisan impact, the
WSJ was merely
reminding readers of its decade-spanning, Pulitzer Prize-winning series of articles about Fells Acres, one of whose central characters had of late also become a national political figure.
Of course, deliberately keeping innocent people in prison and tarred as child rapists involves a level of extreme moral turpitude that many would consider to disqualify a person from seeking public office. So, it's a perfectly relevant thing for them to have brought up, and not only that but they ought to have brought it up. Nevertheless, as you yourself say, the WSJ's motivations are irrelevant; what matters are the facts.
The "mass public hysteria surrounding the case" was during the 80s. By the late 90s-mid 00s, when Coakley involved herself in it, public opinion had actually swung in the other direction, thanks to Dorothy Rabinowitz's reporting. By that point it was well-known and obvious to anyone familiar with the facts of the case that the Amiraults were innocent, and yet Coakley had her office repeatedly fight parole for the Amiraults, and, when despite her efforts the parole board unanimously recommended the release of Gerald, she took the extraordinary step of (successfully) lobbying the governor to block his release.
Coakley could have done
absolutely nothing - simply ignored the case. But no, she went
out of her way to deliberately keep innocent people in prison.
Scott Harshbarger, who was the Middlesex County DA during the initial prosecution, and Jane Swift, who blocked Gerald's release, share in the blame. But at least they have excuses. In Harshbarger's case, during the mid-80s there really was a mass public hysteria, and his office may well have believed its own crap about "recovered memories" and supernatural Satanist powers. In Swift's case, she was acting under a formal recommendation from Coakley. Coakley has no excuse for acting in the way she did. And, Harshbarger and Swift are not currently running for office. (Their gubernatorial campaigns in 1998 and 2002 were both unsuccessful in part because of their actions related to the Fells Acres case).
We also have the case of Kenny Waters; after it was proven that he could not possibly have committed the murder he was imprisoned for, Coakley fought tooth and nail and used every delaying tactic in the book to prevent his release. It's a pattern of extremely disturbing behavior on her part.