The conversations, which are in an early phase, largely involve members of Congress who back Sanders (I-Vt.) reaching out to those in Warren’s camp to explore the prospect that Warren (D-Mass.) might endorse him. They are also appealing to Warren’s supporters to switch their allegiance to Sanders, according two people with direct knowledge of the conversations who spoke on the condition of anonymity to discuss delicate discussions that are supposed to be confidential.

Warren associates and the camp of former vice president Joe Biden also had talks about a potential endorsement if she drops out, according to two people familiar with the conversations.

The whirlwind of activity reflects the rapid changes in a Democratic primary that is still very much in transition. As late as Tuesday, many Warren allies believed she would stay in the race until the Democratic convention, despite her poor showing to date in the primaries, in hopes of retaining her clout and influencing the eventual nominee.