Gov. Rod Blagojevich could tap virtually anyone to replace Obama in the U.S. Senate. The only restrictions are that the person must be at least 30 years old, a U.S. citizen for at least nine years and an Illinois resident.
Several Democratic politicians already have emerged as possible replacements -- including Congressman Jesse Jackson Jr. and Illinois Veterans Affairs Director Tammy Duckworth.
Some have even suggested that retiring Illinois Senate President Emil Jones may succeed Obama -- at least on an interim basis.
Whoever is appointed will fill out the rest of Obama's six-year term, which ends in January 2011. While the law sets no timetable, the appointment is likely before the 111th Congress begins on Jan. 3.