NEW: The Senate is paralyzed over a filibuster clash, with high stakes for Joe Biden's agenda. McConnell opposes a rules package unless Dems pledge to keep the 60-vote threshold, in essence filibustering a transfer of power. Dems say hell no. What now? nbcnews.com/politics/congres…

Scooplet here: Progressive group @accountable_us calls on @SenSchumer to NUKE the filibuster to pass a Senate organizing resolution if McConnell doesn't relent. And so it begins. nbcnews.com/politics/congres…

Democrats already run the Senate floor. But without an organizing resolution, Republicans still control the committees — an unusual power for a minority party. As a result, Biden's legislative agenda can't get off the ground. nbcnews.com/politics/congres…

For now, Democrats don't have the votes to go nuclear. Among the supporters of the 60-vote rule: @kyrstensinema. "Kyrsten is against eliminating the filibuster," a Sinema spokeswoman says. nbcnews.com/politics/congres…

.@Sen_JoeManchin also wants to preserve the filibuster. He predicts Republicans will be constructive partners: "They know we all have to work together. You just can't basically be objectionable to everything just because you're in the minority now." nbcnews.com/politics/congres…