Both finalists -- two-time Republican presidential hopeful Alan Keyes and former Deputy Drug Cczar Dr. Andrea Grubb-Barthwell -- are African-Americans, WTTW-TV, Chicago, said.
Keyes lives in Maryland, where he twice ran unsuccessfully for a Senate seat. Grubb-Barthwell is a former Democrat.
Party committeemen will name their nominee Wednesday to face Democrat Barack Obama, also an African-American.
"We've come down to two very, very good candidates," said State Republican Party Chairman Judy Baar Topinka.
The party's 19-member State Central Committee spent Tuesday listening to a dozen potential candidates explain why they should replace Illinois primary winner Jack Ryan on the fall ballot.
Ryan withdrew five weeks ago amid a scandal over allegations he tried to pressure his former wife to perform sex acts in front of strangers at sex clubs.