By the way: when I was looking into the Matt Bai article earlier today, I wound up running into a terrific reported piece by Cokie and Steven Roberts on voter unrest. In 1980; mid-June, 1980, actually, post-primaries, pre-conventions. It's from the NYT Magazine (pdf), and I enjoyed reading it quite a bit. Lots of interviews with lifelong Dems, many 2nd and 3rd generation Dems, ready to jump, as of course many of them would later that year. Also, it's fun to read quotations from early-career Barbara Mikulski and Chris Dodd, plus a bonus appearance by a certain Baltimore pol who is mostly known to us now for his daughter, not his own career.
Oh, and you'll be glad to know that without an internet to blame for everything, it's that newfangled television that's disrupting traditional ties, including party ties. Yup, at least as late as 1980, TV was still the newish thing that was destroying traditional politics. Which means that we'll be seeing "the internet is changing everything" stories until Ezra Klein is drawing social security. At least.
(Yes, I know: sometimes, the technology really does change things. It isn't destroying political parties now, however. And it doesn't change the fundamental formula: it's tougher to be the in-party during bad times than during good times).