Congresswoman Tammy Duckworth's (D-IL,8) Democratic bid for the U.S. Senate has garnered the support of U.S. Sen. Dick Durbin (D-IL).

Durbin announced his endorsement of Duckworth's Senate run on Thursday, writing in a fundraising letter to supporters that "Duckworth is running to represent Illinois in the U.S. Senate in an amazing journey from the battlefields of Iraq to the campaign battleground in Illinois."

"Tammy is no stranger to tough challenges, but to win this race, she is going to need our full support. Join me in backing Tammy's campaign for U.S. Senate by contributing today," Durbin added. "Illinois families deserve a champion like Tammy Duckworth fighting for them in the U.S. Senate."

In Illinois' Democratic primary race for the U.S. Senate, Duckworth will go up against Urban League President and CEO Andrea Zopp, who confirmed last month that she is entering the race. The candidate who wins the Democratic nomination will face U.S. Sen. Mark Kirk (R-IL).

In response to Durbin's endorsement of Duckworth, Kirk campaign spokesman Kevin Artl said, "Dick Durbin is once again choosing political party over Illinois."

"By hand-picking Senator Kirk's opponent," Artl said, "he abandons the bipartisan partnership that they have cultivated on behalf of Illinois."

For her part, Zopp said in an interview with the Chicago Sun-Times that Durbin's endorsement of Duckworth was not unexpected.

"That said, the calls that I have received from across the city, county and state since launching my campaign this week are firm indications that there are many looking to me to provide a strong alternative as a barrier-breaking, African-American woman with a 30-year history of public private and nonprofit experience, knowledge and success," Zopp said.