Holder Is "Odd Man Out" Tonight

CBS News White House correspondent Mark Knoller reports that Attorney General Eric Holder will not attend President Obama's address to the Joint Session of Congress tonight, according to a White House source.

This move is made before all presidential addresses to Congress and other similar events so that in case of an attack or disaster at the Capitol, a relatively high-ranking official in the presidential line of succession can step in and govern.

While everyone obviously hopes that such a tragedy does not take place, one only needs to watch a show like "24" to think about what would happen if the unthinkable did occur: It's good to know that there are plans in place, even without Jack Bauer.

Earlier today, as is now customary before all State of the Union and other big events, the Department of Homeland Security designated tonight's event to be a "National Special Security Event." That means the U.S. Secret Service will be the lead federal agency for the security plan and that other federal security resources will be deployed.

At the Inauguration a month ago, Defense Secretary Robert Gates stayed behind at an undisclosed location.

As Hotsheet reported at the time, according to the Presidential Succession Act of 1947, if the president and vice president are both unable to fulfill their duties the line of succession follows to the Speaker of the House, the president pro tempore of the Senate (traditionally the senior member of the majority party) and then Cabinet members beginning with the Secretary of the Treasury and the Secretary of Defense. You can see the full list here.

By the way, you can see the first excerpt of the president's speech here. The speech is live tonight at 9 p.m. ET. CBS News will have live coverage which you can also watch here at CBSNews.com. Following network coverage at 10:30 p.m. ET, we will have a Web-only special here hosted by Katie Couric. Guests on the show include Sen. John McCain and White House Press Secretary Robert Gibbs. The show will also feature answers to your questions which you can submit now by clicking here.