What led Opposition Leader Simon Crean to excise the Badgerys Creek airport from Labor Party policy a couple of months ago? The electoral numbers must have been compelling to justify all that grief.

The stock answer is that it was all about aircraft noise in those outer western Sydney constituencies. If Labor is to regain power nationally, it must win back those seats.

You might think that west Sydney offers a smorgasbord of potential electoral gains, but it doesn't.

Labor can extract a maximum three extra seats from the west, and only one of those looks remotely plausible.

That possible gain is Parramatta, which isn't outer at all but snuggles up to John Howard's blue-ribbon electorate of Bennelong.

You wouldn't know it from the fanfare accompanying its capture by the Liberals in 1996, but it has been held by Labor for only 20 of its 102 years.

There's Lindsay, around Penrith, held by Jackie Kelly. Created in 1984 and Labor-held for 12 years, this seems to be the loss that still really rankles. But Lindsay defected mainly because its wallet outgrew its allegiance; its demographics now more resemble a typical Liberal seat than a Labor one.

Next to Lindsay is Macarthur, where Badgerys Creek is. At every election since its creation in 1949, Macarthur voters have backed the party that formed government.

Those three seats are all that's on offer out west: 13 other seats could possibly be classified western Sydney but Labor holds them all.

So if raw seat numbers don't explain the Badgerys Creek decision, what does? Perhaps Australia's oldest party so identifies its soul with western Sydney that pragmatism doesn't come into it.

Labor would move heaven and earth for just a shot at Lindsay alone. Maybe its strategists are confusing cause and effect.

Gough Whitlam rode to power in 1972 through the outer suburbs of the capital cities, including west Sydney. Sydney being the centre of the universe, getting it right there means the rest will follow.

More specifically, Macarthur has always picked the winner, so bag Macarthur and the Lodge is yours. Those are the loopy explanations, but at least they involve victory.

More likely is that internal polling is so dire it's about damage control. Even in this scenario, however, the possible losses don't validate the headache - unless it's all about the member for Werriwa.

Immediately east of Macarthur, and sharing Campbelltown with it, Werriwa is true-blue Labor. Whitlam was a former representative, and shadow Treasurer Mark Latham holds it by a cushy 8 per cent.

However, with each day it becomes more like Lindsay and Macarthur; wealthier and more Liberal-leaning. Losing Werriwa would cut short a brilliant career.

None of this makes the Badgerys Creek decision look rational. An outsider unimbued with the tribal mysteries of the ALP might suggest that political capital would be better used out in the regions, where elections are decided, but Labor is obsessed with western Sydney.

Peter Brent is editor of mumble.com.au, a website that looks at electoral behaviour.