'What if someone has cancer?'
That is why Trump insists that any medical plan will respect pre-existing condtions which some of his opponents do not want to happen.
'What if someone can't work? '
If they are ill and cannot work, then they will be looked after.
'Or can't find work at all?'
They will find work because Trump said "I will be the biggest job creator in US history". Trump is ending the globalists' game, which is why Davos and the world's political class are so frightened of him, he is bringing jobs back to America and tearing up the globalists' trade deals and climate change deals.
'What about their children?'
He is scrapping Common Core education and ending America spending the most per head on education and only being number 30 in the world in terms of education results. People will have jobs again, they will have better wages, the globalists' plans will end and "Aemerica will be great again". Everybody wil do well apart from the global political class and Davos.