Taylor said no details were final and Bragg had been pulled for a quiet chat.Labor, the Liberals and the Nationals — all in a muddle on migration.It sounds like perfect political fodder for One Nation, which has built its political insurgency on the premise that it is the only party capable of "plain speaking" on migration.Except that Pauline Hanson's party may be even more muddled than the others.Its "target" of 130,000 was at first a temporary migration target, or possibly temporary and permanent; it is now permanent, but only temporarily Got that?There is a reason this stuff is hard, even for someone whose desire to cut migration is as unrepentant as Hanson's: for all the focus on the level of migration, its causes are murky, and it is harder for politicians to control than they would like to admit.For starters, the main figure everyone seems determined to talk about — net overseas migration (or "the NOM") — is almost universally misunderstood.For one thing, it is not actually a measure of "migrants" at all, at least in the way they are conventionally understood in the political debate — or at least not just migrants.It tracks arrivals and departures of both foreigners and Australians, excluding short-term visits.And because it measures inflows and outflows, it is not a reliable measure of how many migrants are actually in Australia at any one time