Two factors from as far back as November 2016 may shed a little light on the events of the week of 12-18 January 2020:
1. After losing in 2016, Hillary wears purple. Warren emulates her immediately.
2. Beginning in late summer/early fall of her 2020 campaign, Warren starts wearing purple as a signature color.
These events all took place the week of 12-18 January 2020:
3. Trump begins attacking Sanders as "Crazy Bernie".
4. Warren accuses Bernie of making sexist remarks, a charge even Fox News denounces.
5. Biden announces Warren that is a possible VP running mate.
6. In the aftermath of the presidential debate, the hastag #CNNisTrash trends on Twitter.
7. Also after the debate, hoards of Warren donors contact Act Blue demanding back money they had donated to Warren's campaign.
8. Bernie jumps in the polls and has huge increases in donations and number of donors.