Washington ( CNN ) -- A federal judge from Montana and the dean of Harvard 's law school are among several names being added to the short list of potential nominees to the U.S. Supreme Court , a government source said . Sidney Thomas , a 14-year veteran on the U.S. Court of Appeals for the 9th Circuit , is being vetted by the White House , said the source , who has been regularly consulted in the selection process . Two women who were not on other published lists of potential candidates are now being seriously considered . Harvard Law school dean Martha Minow has been on the school 's faculty since 1981 . And Elizabeth Warren heads the Congressional Oversight Panel , which reviews government efforts to boost the shaky financial and private investment sector . Neither woman has judicial experience . Sources close to the selection process said the new names represent an effort to expand what had been a short list of candidates , many of them left over after last year 's court vacancy was filled by Justice Sonia Sotomayor . Some White House officials have been urging the president to expand the list of possibles to include more non-judges and people with different backgrounds and from other regions of the country . All the current justices except the retiring John Paul Stevens are Ivy League law school graduates . Thomas , who is white , was born in Bozeman , Montana , in 1953 . He is little-known and has attracted little fanfare beyond the San Francisco , California-based court , which is considered the most liberal among the nation 's 13 appeals courts . Among rulings he authored was a 2006 decision in Nadarajah v. Gonzalez , in which Thomas concluded that the government illegally detained Ahilan Nadarajah for four years while the Justice Department appealed a grant of asylum . The man is a member of the Tamil ethnic minority and asserted that he was tortured and persecuted by members of the Sinhalese majority . Minow is the daughter of former Federal Communications Commission head Newt Minow . She clerked for former Justice Thurgood Marshall . In her mid-50s , Minow replaced as dean the woman considered near the top of potential high court nominees , Elena Kagan , now solicitor general . Warren is also a Harvard law professor . She has been a regular on the talk-show circuit , including CNN , to discuss the economy 's effect on families . The Oklahoma native has also co-authored two books with her daughter . One name mentioned by some analysts for years as a potential blockbuster choice has been all but ruled out for consideration . Supporters of Hillary Clinton have long touted her credentials , but White House spokesman Tommy Vietor said Monday that the president `` thinks Secretary Clinton is doing an excellent job as secretary of state and wants her to remain in that position . '' The White House has given no indication when Obama will name a successor to Stevens , who announced Friday that he will retire this year . Stevens has been on the high court nearly 35 years and leads the four-justice liberal bloc .
Appellate judge , Harvard law dean , Harvard professor among possibles . Sources say White House attempting to look beyond last year 's candidates . Justice John Paul Stevens announced his retirement last week .