I think the following comment is a stretch and how and why it errors questions the author’s premise:
“Over the last 10 months we have seen Speaker Nancy Pelosi (D-CA) struggle with keeping her caucus in check. Months ago, she made it very clear the House would not move forward with impeaching President Donald Trump because of the it was an issue that divided Americans. She lost that fight to the extreme progressives of her party, in particular the freshman Squad consisting of Reps. Alexandria Ocasio-Cortez (D-NY), Ilhan Omar (D-MN), Rashida Tlaib (D-MI) and Ayanna Pressley (D-MA).”
That comment suggests that Mr Schiff is not doing exactly what Pelosi wants, yet it is clear he is doing exactly what Pelosi wants. I doubt seriosuly that Schiff is acting to satisfy the freshman “squad” and not Pelosi.
These extreme progressives are nothing more than a quartet of nitwits, and they have no power in Pelosi's caucus at all.
In the impeachment debacle, Pelosi has lost the fight to the party's wealthy donors, not anyone in her caucus.