Rep. Danny Davis backs Jackson over Giannoulias

Rep. Danny Davis (D-Ill.) is backing Chicago Urban League President Cheryle Robinson Jackson in the state's Democratic Senate primary.

Davis signaled his support with a $2,000 contribution to Jackson on Sept. 29, according to his third quarter federal financial filing. Davis spokesman Ira Cohen said the congressman will join a number of elected officials Sunday to formally endorse Jackson.

State Treasurer Alexi Giannoulias is the establishment favorite in the primary, but Jackson, the only African-American candidate in a crowded field, is garnering the support of black members of Congress. African-Americans are a large voter block in statewide Democratic primaries in Illinois.

Davis's fellow CBC member, Rep. Bobby Rush, endorsed Jackson in late August. Rep. Jesse Jackson Jr. (no relation), the third CBC member in the state's delegation, has not endorsed.

Cheryle Robinson Jackson has also been endorsed by EMILY's List.

Davis is currently eyeing a run for president of the Cook County Board of Commissioners.

UPDATE: Davis's spokesman initially said Davis had already endorsed Jackson. This post has been updated ro reflect that the endorsement is forthcoming.