Based on preliminary, unofficial data:
1. A poll taken immediately after the primary had Tsongas at 51%; she appears to have ended there. Exactly as in the primary, she never gained a vote along the way; never convinced an undecided voter.
2. Tsongas won because of a liberal upper-middle-class suburbia vote; aka an Acton/Concord/Sudbury/Wayland vote; aka a Middlesex vote; aka a Cambridge-extension vote.
3. Tsongas almost lost because Democrats who voted for other candidates in the primary weren't much interested in her -- if just the core Democrats who voted in the party's primary had voted Democrat in the general, she would have had 55,800 votes. She only got 54,300.
4. In particular, Eileen Donoghue's voters in Lowell, Methuen, Dracut and Tyngsborough; Barry Finegold's voters in Andover; and Jim Miceli's voters in Tewksbury abandoned the party in the general election.