GET TO KNOW RULE IV…. With the Senate Democratic caucus up to 59 seats, chances are pretty good that President Obama’s Supreme Court nominee will be confirmed, no matter how big a fit the right throws. Even if Republicans abandon everything they said during the Bush years and launched a filibuster, it’d be pretty difficult to sustain it.

The problem, however, might be getting the nominee to the floor.

The Senate Judiciary Committee has a procedural rule, Rule IV to be specific, that will require judicial nominees to get at least one vote from the minority party in order to advance to a vote of the full Senate. Up until last week, that one vote was likely to be Sen. Arlen Specter, the most moderate Republican on the committee.

Specter has, of course, become an ostensible Dem, and now there are no GOP moderates on the Judiciary Committee.

The current Republican Judiciary Committee members are: Orrin Hatch, Chuck Grassley, Jon Kyl, Jeff Sessions, Lindsey Graham, John Cornyn, and Tom Coburn (Roll Call is reporting that Hatch or Session — both conservatives — are Specter’s potential successors for the ranking slot). Most of these Republicans are pretty conservative save Graham, who was a member of the Gang of 14 which, you may remember, came up with the solution to avoid the nuclear option on judges.

If Obama comes up with a nominee opposed by the right, Graham will be under a lot of pressure to block the appointment — essentially an insurmountable committee filibuster. Rahm may want to put Graham’s # on speed dial.

For what it’s worth, Graham, at least for now, doesn’t sound like he’s inclined to block the eventual nominee.

“The only way the Obama administration can screw this up is to nominate someone who is a radical,” said Sen. Lindsey O. Graham (R-S.C.), a senior member of the Judiciary Committee. Graham said Republicans understood that “you’re basically going to replace one liberal with another.”

Just one more angle to keep an eye on.

Our ideas can save democracy... But we need your help! Donate Now!

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.