So the way I could see this working for her is have Bernie Sanders come and endorse her right out the gate (I doubt he'd be up for being her running mate, but it'd probably be an even better run if he accepted that).
Ol' boy had been VERY effective at breaking into right - leaning spaces and I could see him contributing to getting the historically Democrat (but not recently Democrat) voter out for AOC.
My real concern is the party leaders. I could see them trying to hold back resources and effectively pulling the same moves they pulled in Bernie to hold her down.
I think I'd depends on what you mean by secure.
So to give you an idea of how that'd work (at least my understanding of it):
On the face of it and with a "normie" home network, this is probably okay.
However, if you (as an example) run a local DNS server (like Pi-Hole) its possible that your DNS traffic gets send through normal (and potentially non - encrypted means) channels to the DNS server and then forwarded out to the wider internet. This could allow an ISP to get an idea of what you're looking at with your VPN (since they'll be able to see that you're using a VPN, this is not a difficult thing to correlate)
So really the answer is it depends. I'd minimize risks by leaving LAN connections off, unless you really need it, but that's making a bunch of assumptions about your specific needs and threat model.