KNOWN KNOWNS:

Supreme Court Short List Shows Ties to Obama: Personal Connections Have Played a Role in Past Nominations (JOAN BISKUPIC, April 24, 2010, ABC)

Among the ways potential candidates' lives have intersected with the orbit of Obama:

" Harvard Law School, where Obama was in the class of 1991: U.S. Solicitor General Elena Kagan was in the class of 1986; U.S. Appeals Court Judge Merrick Garland, 1977; Michigan Gov. Jennifer Granholm, 1987.

" University of Chicago Law School, where Obama taught from 1992 to 2004: Kagan was a law professor 1995-97; U.S. Appeals Court Judge Diane Wood taught and held various positions from associate dean to part-time senior lecturer since 1981.

" Current administration: After Obama took office in January 2009, he chose Kagan to be U.S. solicitor general and Janet Napolitano to be Homeland Security secretary.

" Acquaintances and other associations: Obama has ties to Wood from more than a decade in Chicago legal circles. Granholm, who campaigned for Obama in the 2008 presidential race, played Sarah Palin as Joe Biden rehearsed for the vice presidential debate.