Did Bernie inadvertently give MAGA the blue print to come into power while trying to educate voters?
No.
None of this (nor any other strategy) was any sort of recipe that the Republicans did not already have. Bernie was just saying out loud what he thought was a key overall strategy they are following, so that there would be some sunlight shone on it.
I’m not sure if it speaks strongly to this strategy of sewing divisiveness, but “Democracy In Chains” gives a good idea of how long the Republicans have been pounding away on certain issues, and with what goals in mind.