Sotomayor will make it out of committee, I (basically) guarantee it

When Arlen Specter switched parties, a nugget of contrarian wisdom arose suggesting that his move might actually might things more difficult for Obama's next SCOTUS pick.

Why? Judiciary Committee rules require that at least one member of the minority party--Republicans in this case--must agree to bring a committee motion to a vote. Specter was seen as the most likely Republican vote--without him, a more conservative Republican would have to give way. If all seven current Judiciary Republicans hold firm, they could theoretically prevent a committee vote to report Sonia Sotomayor's nomination to the floor. Think of it as a committee cloture motion.

But Republicans will almost certainly not use this tactic. Understanding why requires a little background on committee procedure.

After voting to end debate, the committee can vote to report a SCOTUS nominee in one of three ways: (1) vote to report the nominee out of committee "favorably;" (2) vote to report the nominee out of committee "unfavorably;" or (3) vote to report the nominee out of committee with no recommendation.

Even SCOTUS nominees who face huge opposition are voted out of committee one way or another. Robert Bork, for example, whose nomination went on to fail in the full Senate by a vote of 42 to 58, still made it to the floor. The committee simply chose to report him "unfavorably." Clarence Thomas was voted out of committee with no recommendation.

As far as I can tell, not once since the Judiciary Committee began regularly examining nominees in the mid 19th century has the committee refused to take action on a nomination. If you have some free time, you can read this 2006 Congressional Research Service report on the history of SCOTUS nominations. (The full Senate, not just the Judiciary Committee, voted to table a few of John Tyler's nominations in 1844. When Andrew Johnson, whom the House has recently impeached, nominated Henry Stanberry, the Senate chose to reduce the number of SCOTUS seats rather than consider the nomination.)

The reason the committee filibuster is so rare (non-existent), is two fold. First, the opposition party still has multiple opportunities to express their discontent and potentially block the nominee. They could vote to report the nominee unfavorably (a huge blow), they could launch a filibuster in the full Senate, or they could simply oppose the nomination in the full Senate when he or she comes up for a final vote.

Second, if Republicans were to prevent a committee vote, they'd be opening themselves up to charges of the most extreme obstructionism ever seen on a Supreme Court nominee. Even when a minority threatens a 40-senator filibuster, they face charges of obstructionism. It'd be politically untenable for seven, conservative Republicans to filibuster a popular President's nominee in the committee stage. Essentially, they'd be--hold your breath--preventing a vote on a vote to allow a vote to vote about Sotomayor.*

Don't count on it.

Of course, it's possible a nominee might become so unpopular that the President would withdraw him or her before the committee had a chance to kill the nomination (i.e. Harriet Miers). But a nominee who has the full support of a popular president will not be blocked in committee by the minority party.

*In order, the votes would be: (1) end committee debate; (2) vote to report nomination out of committee; (3) cloture motion in the Senate; (4) final vote on nominee