Very much this. Democrats largely saw big wins for state-wide elections in my state (North Carolina). Yet, Trump took the electors, implying that there were people who voted for Democrats locally but not for Kamala. I know people on this site like to say that MAGA is what America wanted, but I think the support is tentative at best. If a good choice from Democrats emerges, they can definitely sweep.
A shortage of engineers willing to work for Musk-led companies, maybe. Tesla is well-known in tech circles to have awful work culture. You can only survive with high turnover like that for so long before most American engineers know that there are much greener pastures.