Peter Costello just won't go away. He does, after all, love the media attention; and the fawning of right-wing neo-liberals in the party. Much has been made of the fact that Peter Costello won't comment about leadership speculation, but he doesn't have to: his acolytes will continue to talk about it, and elements within the media keep driving it as a "story".
Costelo, or his followers, have dragged Malcolm Turnbull's leadership away from the more reasonable centre-right, small-l Liberalism, back towards the more extreme neo-liberalist views of Costello. The Liberal Party's, and Turnbull's, position on each of the following has lurched to the right because of Costello's influence: the economic stimulus, fair workplace legislation, and climate change.
Foreign Minister Stephen Smith is reported as saying that the federal opposition's position on several key issues won't change even if Peter Costello became their new leader. Well, yes; given that Costello has effecgtively dragged the Liberal Party to his right-wing policies on these issues.
But is Peter Costello simply being a right-wing idealogue, using his supporters to effect right-wing changes in policy? Or, is Peter Costello a tool of the right-wing to wrest power from the more moderate Turnbull? His seemingly increasing support from within the party is testament to the work of his acolytes. That Malcolm Turnbull is looking over his shoulder indicates his tenure is likely to be replaced sooner, rather than later, pehaps after the (7-week!) autumn break from Parliament.