This is a political power struggle, and it's bad news for Chuck Schumer and the Democratic establishment while being a win for progressives pushing to cut off war funding.

• Senator Chris Van Hollen wants Democrats to refuse to fund the government past December 11th unless it stops funding the Iran war, and he's now openly considering a run against Schumer for Senate Majority Leader.
• Bernie Sanders publicly broke with Schumer, saying he won't support him for another term as Democratic leader, and other senators like Elissa Slotkin are signaling the same.
• Removing Schumer only takes a simple majority in a closed-door vote, and roughly a dozen senators are already hard no's, putting him closer to being ousted than House leader Hakeem Jeffries, who hasn't faced the same pressure.
• Schumer insists he's still confident he'll be reelected leader, even as protesters gathered outside his office and polling shows most voters view him unfavorably and want him replaced.

Outlook: The fight comes to a head with a leadership vote expected in early December, and whether Van Hollen formally enters the race will determine if Schumer faces real competition.