As Greg says, the danger here is that a bipartisan package might “dilute” reform — indeed, it’s easy to imagine something that’s so diluted that it wouldn’t fix any of the obvious dysfunction of the current 60 vote Senate.
On the other hand, if the main thing at risk is Jeff Merkley’s “talking filibuster” plan, then Democrats could be in good shape after all; while many senators on both sides of the aisle appear to believe it’s a big deal, I don’t think it would work at all, and most Senate scholars, including some who favor significant reform, agree that requiring talking filibusters is generally unlikely to be successful.
The real question is, what should Democrats seek from Republicans in a bipartisan package? My advice: They should focus on nominations. As dysfunctional as the Senate has become on legislation, there’s nothing urgent about legislative filibuster reform during a period of divided government. But nomination reform would make an immediate difference, and there really should be room for a compromise; one, perhaps, that would still allow Republicans (or at least 41 Republicans) to block lifetime judicial appointments in those cases where they really objected to someone and would allow the minority to stir up a fuss when they objected to executive-branch nominations, but would also allow non-controversial nominations to move quickly through the Senate.
Would Republicans go for that? I have no idea. Under the threat of a majority-imposed reform that might threaten them even further, perhaps they might. And it should be something that both wavering and more reform-minded Democrats are willing to live with.
If Republicans aren’t on board for that kind of deal, then Democrats should go ahead and impose something. The truth is that as long as they are in the majority, it’s really their responsibility to get the Senate working well, even if it does mean they have to play hardball once in a while.