Filibuster reformers such as Ed Kilgore respond to such threats by saying, in effect, bring it on -- and he and Kevin Drum ask a good question:
Can Republicans really obstruct the Senate even more than they do now if they put their minds to it?The answer? Yes. But it's not a reason to avoid reform.
As far as what Republicans can do: they haven't quite blocked everything. Most things, but not everything. Quite a few nominations have come to the Senate floor without needing cloture. In many cases, they don't even insist on a recorded vote. Not only that, but Republicans usually don't insist on maximizing disruption. They usually don't demand the 30 hours of post-debate time that they are entitled to under the rules; they usually yield it back. They usually don't demand serial cloture votes on minor legislation. They don't object to switching away from a bill that's on the floor to another bill (remember, the modern tracking system which allows the Senate to get work done while a filibuster is underway is a benefit for the majority party, not the minority). And I'm sure that if you asked Greg Koger or Sarah Binder or Steve Smith, you could get a longer list of potential tools that the minority party hasn't used yet.
So, yes, they could do a lot more to obstruct than they currently do.
However. Would they shut down the Senate if Democrats forced through a rules change by majority vote? Almost certainly, the answer is no -- because nothing about reforming the rules would change the incentives for the minority party to obstruct. Take nominations, for example. Why would Republicans have a greater incentive to obstruct them after majority-imposed reform? To punish the majority? What does that give them?
Indeed: after the majority shows they are willing to impose rule change by simple majority, the minority party may have reduced incentives to "shut down" the Senate. After all, what's been done once could be done again. So if Republicans really did start forcing, for example, a week of floor time to get minor executive branch nominees confirmed, Democrats could threaten to change the rules to eliminate that option.
Two caveats. One is that an immediate post-reform tantrum is certainly possible. It's more likely that it would be symbolic than across-the-board, but it wouldn't be surprising if Republicans do shut things down for a week or so before resuming "normal" filibustering.
The other is that normal filibustering will itself be altered, at least perhaps, by whatever the actual rules changes wind up being. The way this will actually work is that once the details of reform are made public and then passed, minority party rules experts will study them and determine the best way to continue blocking things. Assuming that's possible under the new rules -- and that appears to be Harry Reid's intent, to change but not end filibustering -- then we'll get some sort of new-look filibusters, which may or may not be less dysfunctional than what we have now.
But no: Democrats should not worry too much about threats to "shut down" the Senate, even though Republicans almost certainly would be able to do it. Basically, if they didn't do it so far, they had good reasons not to do it, and those reasons would not disappear with reform.