It can lead to what we're seeing here: frequent short negotiating sessions that are interrupted so that the negotiator on a short leash can confer with his principals, pass on the latest message and devise a response. It short circuits one of the features of an intense negotiation, which is to create a pressure-cooker environment that melts away the extraneous issues and forces the parties to deal with the core disagreements.
If you've ever been in a negotiation where the opposite side is a loosely associated group or committee, like the House GOP conference is, you know how frustrating it can be not to have a fully empowered negotiator representing them. All of your efforts to nail down the specifics are rebuffed with marshmellowy vagueness. The harder you press, the mushier they get.
It's not clear whether Boehner is so constrained because he hasn't yet been able to win over his entire caucus but still hopes to -- or because he knows going in that he will never be able to win them over. Either way, if my sense of this is right, it means the Democrats are dealing with someone who doesn't have the power to agree to a deal -- which makes striking a deal very tough.