I partly agree with Tom - Democrats are deeply dissatisfied with their party and eager for something new. It's ludicrous to suggest they want something more moderate or centrist when the leadership of the party is firmly in the camp of Clinton-era centrism, the more progressive voices within the party are always kept at arms length despite their popularity, and all three of its last presidential candidates ran as centrists. The idea that Democrats are just way too left-wing is a cynical strategy from conservatives to try and get them to move right, at which point they too move right and continue to insist that the Democrats need to move right, thereby moving the Overton window right as well. There isn't a single person in the world who would vote Democratic if only the party were slightly less leftist. Anyone like that is already voting Republican. I also don't believe that Elon was ever especially liked or admired by the left. I've only ever heard conservatives make that claim, not leftists, and there doesn't seem to be any good evidence backing it up beyond the fact that Elon sells electric vehicles. I don't know who you're claiming is trying to rehabilitate his reputation, but even if Elon were making an effort to backtrack from his right-wing politics and reinvent himself as a progressive (and a quick glance at his Twitter will show that he very much is not), I don't see any reason why progressive voters would suddenly forgive him for helping Trump get reelected and then butchering the federal government so that he could make more money.
We might learn some lessons from the recent victory of Zohran Mamdani over Andrew Cuomo in the Democratic mayoral primary of New York. Democratic voters made their priorities clear by supporting Mamdami's strongly progressive policies over Cuomo's business-as-usual centrism, and also by rejecting Cuomo, who, unlike Elon, had previously been well-liked by Democrats until he resigned as governor in the wake of a sexual scandal. That's two strikes against Elon - Democratic voters want progressive policies, not even more centrism, and they're not interested in giving multiple chances to people disgraced by scandal. Oh, but I will agree with you that Republican voters are content with what they have. Trump has shown us repeatedly what kind of person he is, and Republicans are unanimously okay with it. They wouldn't hire him, work for him, hang out with him, lend money to him, or leave their girlfriend alone with him for five minutes - but they will vote for him. In the face of that kind of solidarity, Elon trying to win over his voters is a ridiculous idea, but as I've said before, Elon is nowhere near as smart as he and his followers think he is.