President Obama is believed to have had a short list to replace Supreme Court Justices David Souter.

One possibility is the current U.S. Solicitor General, Elena Kagan. She's a former law professor at Obama's alma mater, Harvard University.

Another well-known name who might make the list is Massachusetts Gov. Deval Patrick.

Most of the rest of the likely possibilities are sitting federal judges. Among them are Ruben Castillo of the U.S. District Court for the Northern District of Illinois, Margaret McKeown of the 9th U.S. Circuit Court of Appeals in San Francisco, and Diane Wood of the 7th U.S. Circuit Court of Appeals in Chicago.

Law professors Pam Karlan of Stanford and Cass Sunstein of Harvard might also make the list.