That means Republicans would have to threaten filibusters and other obstacles to force passage of a new resolution allowing for such a switchover [of majority control in the Senate].Excuse me. But a Lieberman switch isn't needed for the Republicans to use filibusters and Senate rules to block legislation. They're doing that right now without the majority. Unlike the Democrats, the Republicans have been very comfortable using the filibuster already this session despite their condemnation of the tactic when they had the majority.
So while Lieberman cannot directly play kingmaker, that is quite a monkey wrench he is holding.
I'm a very lucky person with every allergy known to man but still happy to be enjoying a wonderful life living in the best place in the world!