Neither is a great option.For now, Taylor is keeping the focus on the big broken promise.Anthony Albanese and Chalmers are yet to give a convincing explanation as to how exactly "circumstances changed" since the prime minister flatly told voters at the election that he would not touch negative gearing or capital gains tax.Everyone in Labor knows this creates a credibility problem How this cap might be enforced, and which migration streams would be restricted, remains unclear.The opposition leader will also re-commit to a $5 billion housing infrastructure fund promised by Peter Dutton.Coalition figures are also hinting at a permanent fix to bracket creep, by promising to index tax thresholds to inflation, an idea Dutton floated as an "aspirational" aim in the desperate dying days of last year's election campaign.That would be a big idea, and would grab the attention of younger workers, who are constantly pushed into higher tax brackets by inflation.But ending this "fiscal drag" by indexing tax brackets is also enormously expensive.Then prime minister Malcolm Fraser tried it back in the 1970s, and it didn't last long