Not sure about holds...but there are three ways to keep the nominee from being approved:
1. At least one member of the minority must vote to get the nominee out of committee. (that actually might be for legislation, not judge nominees...will have to check)
2. Once the nominee gets out of committee, debate can be ended with 60 senators voting in the affirmative for invoking cloture. The Donkeys have 59...but I totally count on some kind of "go along to get along" republican to provide the 60th vote...Grahamnesty, McCain, Collins, Snow, or someone else...
3. Once debate is ended, it's a done deal. all they'd need is 50+1.