In the long and restless negotiation between Australia's centre and its western edge, Prime Minister Anthony Albanese arrived in Perth this week to offer something rarer than policy: a promise. Repeating it until repetition itself became the point, he guaranteed that Western Australia's GST floor arrangement — a 75-cent guarantee born of the 2018 Morrison-era deal — would remain untouched for as long as he holds office. The pledge came in direct answer to a Productivity Commission interim report that had called the arrangement a costly mistake worth $23 billion to the federal budget, and it ca