They're not as dumb as you think. They know tariffs will raise prices. What they
think is that tariffs may repatriate manufacturing, leading to more and better jobs and higher wages. Lower prices have resulted from outsourcing, which has resulted in their unemployment and under-employment.
They had a different reaction to price increases under Biden because those were not resulting from pro-American-worker trade policies, or at least were not perceived as such. In reality Biden was doing some things to try to repatriate manufacturing, but these policies were badly communicated if they were telegraphed at all, and they were not enough.
Constantly assuming these people are all just stupid isn't winning back any votes. To be fair: Republicans and MAGA spend a lot of time attacking straw man Democrats and liberals too.
BTW -- I see what they're thinking, but I suspect a lot of repatriated manufacturing will be so heavily automated it will not result in the mass employment gains they're hoping for.