By Greg Giroux

Who did not previously hold Barack Obama ’s Senate seat?

a) Peter Fitzgerald

b) Everett Dirksen

c) Scott Lucas

d) Paul Douglas

Answer: d) Douglas, a Democrat who served from 1949-67, held the Illinois Senate seat that is now held by Democrat Richard J. Durbin , the Senate Majority Whip.

Republican Peter Fitzgerald — not to be confused with U.S. Attorney Patrick Fitzgerald — served from 1999-2004, when he retired and was succeeded by Obama.

Dirksen, a Republican, held the seat from 1951 until his death in 1969. In the 1950 election, Dirksen defeated Lucas, a two-term Democrat who was then the Senate Majority Leader.