Announcements on immigration (various) by the federal Coalition have been hard to miss in recent decades.

From John Howard talking about Asian immigration in the 1980s to Stopping the Boats in 2013, there's always been a lot happening politically in that space.

Opposition Leader Peter Dutton?? no stranger to the vibe as a former home affairs minister?? was back there this week: snapping off the various threads of debate about Jim Chalmers's third budget with the simple proposition that a Coalition government would cut migration and foreign investment in housing to make it easier for Australians to get a home.

In doing so, he honed in with deadly precision on the hot-button issue of our housing crisis.

Any politician is entitled to put forward a policy proposal for fixing a tough policy problem. The Greens, of course, have been running hard on housing for some time.

But there are two particular aspects of Dutton's political strategy which are disturbing.

The first is that he is not just targeting migration's impact on housing.

He told the ABC's 7.30 on Thursday night:

"It's not just housing. People know that if you move suburbs, it's hard to get your kids into school, or into childcare. It's hard to get into a GP because the doctors have closed their books. It's hard to get elective surgery. These factors have all contributed to capacity constraints because of the lack of planning in the migration program."

He has also blamed migrants for "congestion on our roads".

In other words, the opposition leader has opened the doors to migrants being blamed not just for housing shortages but for all these other problems, too.

Dutton's determined to bang this drum

For now, let's leave aside the fact that permanent and temporary migrant workers are filling huge holes in the care and health economies.

But Dutton?? apparently devoid of other major policy issues?? seems determined to bang this drum very loudly between now and the next election.

Previously mooted plans for a nuclear-powered energy future are vaguely drawn out in the background. Even cost-of-living issues seems to have faded in importance.

The significance of a major political leader playing so divisive a card on our community is a step that shouldn't go unnoticed, no matter how inured to it we have become over the years in the wake of Pauline Hanson and "boat people" politics.

It is deadly simple, but very dangerous, politics.

The second aspect of what Dutton is doing which is particularly conspicuous is that he has done it without putting forward a serious proposal that would actually cut migration numbers, or materially affect the housing market.

On Thursday night, he told the House of Representatives a Coalition government would respond to the housing crisis through measures including "rebalancing the migration program and taking decisive action on the housing crisis", which would "free up almost 40,000 additional homes in the first year".

The plan would include a "two-year ban on foreign investors and temporary residents purchasing existing homes in Australia"; reducing "the permanent migration program by 25 per cent ? from 185,000 to 140,000 for the first two years"; ensuring there are "enough" skilled and temporary skilled visas in the building trades; cut refugee and humanitarian programs; reduce "excessive" numbers of foreign students and set a cap on foreign students.

Look, on first blush, it all sounds perfectly reasonable: too many people, not enough houses.

But it is never that simple, as a former home affairs minister should know.

Crunching the migration numbers

The permanent migration program is the smaller part of our overall migration system which is dominated by temporary visa holders ? a development from the Howard years.

The overall net figure for how many people actually arrive in Australia is much higher. It is called the net overseas migration number.

The Morrison government announced an almost identical cut in permanent migration numbers in the 2019 budget, saying the "planning level of the Migration Program will be reduced from 190,000 to 160,000 places for four years from 2019-20".

The pandemic rather disrupted that plan.

But the very same 2019 budget papers were forecasting that net overseas migration would be 271,700 in 2019 (compared to 190,000 permanent arrivals) before dropping ever so marginally to 271,300 in 2020 and then to 263,800 by 2022 (despite the cut of 30,000 permanent places a year).

A big reason for the fact that net overseas migration was not forecast to fall, despite the cut in the permanent number, is that more than half the people who are accepted as permanent migrants are already here when they apply.

So cutting permanent migration doesn't necessarily mean fewer people in, or coming to, the country. Some of the migration pool just changes "class". Others are still able to come here on temporary visas.

Dutton told Radio 2GB on Friday that "at the moment … the government's predicting 528,000 this year" for net overseas migration.

Actually, no. That's the figure for 2022-23 in the budget papers, which say that in the financial year just ending, net overseas migration has already fallen back to 395,000.

It is predicted to fall to 260,000 in 2024-25 (a number Dutton described as "pretty dodgy") and then to about 235,000. (Both numbers notably also less than those forecast in 2019).

Reducing a complex issue to a populist piece of political mischief

But based on the pattern we saw in the Coalition's own 2019 budget?? of little change in overall migration despite planned cuts in the permanent program ? it is the opposition leader's numbers that appear to look "pretty dodgy".

There is lots that the current government has done in the immigration space that has not been, shall we say, a great political success?? notably after last year's High Court decision .

But it has overseen a significant cutback in net overseas migration since the post-pandemic surge.

And just what factors helped create that surge? The sudden return of international students is widely seen as the major factor behind the big jump in post-pandemic net overseas migration, which peaked in 2022-23.

In January 2022, the then prime minister, Scott Morrison, announced the removal of restrictions on how many hours international students could work, arguing we needed them to come here to alleviate workforce shortages, as well as get international education back on track.

The current government put a cap back on working hours in July last year.

Scott Morrison and Peter Dutton were fond of talking over the years about "pull" factors in encouraging people to travel to Australia by boat.

A capacity to work unrestricted hours (which one would think would not leave a lot of time to pursue studies) would seem to have been a pretty strong pull factor behind the huge surge in numbers turning up here in 2022-23. (In fact, it was described by the time as a "ponzi scheme" by the head of the Council for International Education.)

But Dutton is now proposing to once again lift the allowable work hours for international students to 60 hours a fortnight?? a much more generous allowance than countries like the United States, Canada, New Zealand, and the United Kingdom.

Based on past experience, it is hard to see how that idea can possibly represent a coherent part of the Coalition's rhetoric or policy this week.

In the meantime, the complex set of issues that governments need to address on housing get sidelined. The federal government would argue it has done a lot to try to start to address the housing shortage. It is not clear that it is enough. It is not something that can be fixed overnight.

It's a shame, though, a massively complex issue has been reduced to a populist and misleading piece of political mischief.

Laura Tingle is 7.30's chief political correspondent.