Both the House and Senate are leaning strongly for the Republicans according to aggregate polling. If Harris manages to squeak out a win, she will find herself handicapped politically from the get-go in a way we haven't seen since the 1970s with Gerald Ford. This remains a highly plausible scenario, as she is massively out-spending and out-organizing Trump in Pennsylvania. In September, Harris spent $270m to Trump's $78m, and we may see even more disproportionate spending in October.
To Trump's advantage, Harris' media honeymoon seems to have worn off a bit on voters, even while every single article at CNN, MSNBC and ABC is unabashedly pro-Harris. If you count the free media coverage she's getting, her control of public media over Trump is probably 10 to 1.