For right-wing people a basic concept is we against “them”. They are not against healthcare, but against healthcare for “them”. Not against the subsidized bus their mum rides but against busses for “them”. Not against grants for their dad's payments but against giving “them” money.
They are the ones God loves as they are righteous, but not “them” who are wrong. Jesus? Ok, Jesus may pity “them”, but only with a grin.
So when MAGA announced all the cuts the voters' minds read it as: what they will take away from “them” – and that's what they voted for.¹
And this basically is what all this MAGA regrets is about. It's not that they now care about others. Just that they are not “them” and should not be hit.
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¹i.e. also: deport all of “them” but not anyone I like or need