The Nazis lasted 12 years. I'm not saying do nothing, but given how ineffective the opposition has shown itself to be, I question whether "organizing" is going to help much. With poor messaging it could hurt.
I really like the idea behind "Make America Smart Again," but no one is going to be persuaded by being told they're stupid. Give them a chance to get there on their own ;-). Richard Nixon won by a real landslide in 1972 and was history less than two years later. People had simply had enough of him. I don't know what alchemy turns gold into dross - I just know that it does happen.
"The resistance" may mean doing what you can on an individual level to promote fact-checking and critical thinking. Or really listening when your crazy aunt/uncle/niblingo spouts off at Thanksgiving. It might not work great if you're faking it, but if you're genuinely trying to understand? That can be pretty powerful.
BTW, "less than half the population voted" distorts the image. As far as I can tell 2024 is projected to come close to the record turnout of 2020. You don't use the population as the denominator, but rather, registered voters, or perhaps the adult population, though that is also flawed. In any event, this wasn't a low-turnout election.
Say you have 100 voters. You only have to change the mind of one or two of them to flip the election. Or persuade one or two of them to stay home. Trump's raw popular-vote numbers are about what they were in 2020. Harris' raw popular-vote numbers were down a lot from Biden's. Which doesn't matter that much if the lost Dem votes were in California but matters a LOT if they were in Pennsylvania, Ohio, etc.