M0nica
They wouldn't work. All the countries mentioned here as having ID cards have just as much problem with illegal immigrnts as we do, unless, of course, we become a police state like China. Russia and North Korea and flood the streets with a quasi-military police force constantly stopping people to check their papers.
Since illegal immigrants will all be foreign, there will be no point in stopping clearly indigenous people. All the people stopped will need to be have different coloured skin, hair or eyes, this will be massive discrimination of the many millions of people of other ethnic origins who live here legally and have done for generations.
I am not against ID cards I simply cannot see their point. We had a holiday home in France for over 30 years and I cannot ever remember having to produce my passport for identification, except when we bought and sold the house.
Without an identity card in France you cannot access education, health services, banking, housing, purchase of major items and public services.
Not sure how you manage for long without any of those.
As a second home owner you may not have needed your passports much, but I can assure you that as migrants here, we needed passports, translated copies of birth and marriage certificates, proof of taxation etc etc. We now have identity cards and have been asked for them fairly frequently.