Here’s the problem: I never lived through the Reagan admin.. I was 6 !
From my internet research all I can see is him supporting amnesty, he said it clearly in debates in 84 and he signed the bill in 86. For him to then regret this is a huge leap. If a writer suggests this I need better than “According to Meese...”. There’s no quote from Meese directly and in that NPR article there are Reagan aids who said he supported normalization and stuck to it.
Here’s the thing: regardless of whether Reagan can be quoted as admitting a mistake on amnesty, it manifestly WAS a mistake.