Fans of leadership speculation had a good run in the last couple of years of the Howard government, with a new story seemingly every week talking up the chances of a Liberal leadership challenge. But that was nothing compared to this year, when, having already dispatched one leader, the Liberals seem to have a terminal case of uncertainty about the man who replaced him.

As usual, the centre of speculation is Peter Costello. This morning, a fresh run of stories picks up Tony Abbott’s comment yesterday that “If he is going to stay in the parliament, a man of his talent really does need to be in the front row, not sitting on the sidelines.”

There’s no evidence at all that Costello himself has any enthusiasm for the idea. A politician who was seriously contemplating a comeback would be making much more of an effort to prepare the ground and generate favorable publicity. While at some level he may want to keep his options open, the most likely outcome is that he will serve out his term as a local member and retire at the next election.

But Costello’s supporters will resist facing that conclusion for as long as they possibly can, because without the prospect of a Costello leadership they lack anything to hold them together as a group.

Throughout the Howard years, the Costello group was able to define itself as anti-Howard. That meant that, even though most of its members probably thought of themselves as on the “right”, their interstate connections tended to be with the left, because the right nationally was pro-Howard. That made the internal party landscape in Victoria look ideologically confused, since the anti-Costello group (now associated with Ted Baillieu) also pictured itself as on the left.

With Howard gone, and a new leader identified with the party’s left (although he initially won preselection courtesy of the right), any Costello push would play into a very different factional dynamic. Even in a post-ideological landscape, marketing yourself as the alternative to Turnbull would look very different from marketing yourself as the alternative to Howard.

But if Costello disappears from the scene altogether, his supporters will find their lack of a unifying theme all the more debilitating. Not to pretend that party factions in general are ideologically homogeneous, but it’s hard to see how one could survive for long with neither a charismatic leader nor any sort of story to tell the new recruits.

Denial is a natural human reaction to the prospect of a traumatic event. But one day, the Costello supporters are going to have to move on.