Rep. Jan Schakowsky (D) endorsed state Treasurer Alexi Giannoulias (D) over the weekend, becoming the fifth Member of the state’s Congressional delegation to support the party’s frontrunner in the race for President Barack Obama’s former Senate seat.“Alexi Giannoulias is the best candidate to retain President Obama’s seat because he has the courage to take on powerful interests and stand up for Illinois families,— Schakowsky said in a statement. “He supports health-insurance reform that will reign in the soaring costs of premiums and protect families from losing coverage during these difficult economic times.—Schakowsky’s endorsement is important because it could help Giannoulias among women voters. He faces former Chicago Urban League President Cheryle Robinson Jackson in the Democratic primary, and she has the backing of the influential women’s group EMILY’s List. Other candidates running in the February Democratic primary are former Chicago Inspector General David Hoffman and attorney Jacob Meister. This isn’t the first race in which Schakowsky has backed Giannoulias. She was one of the first Members in the state’s Congressional delegation to endorse his bid for state treasurer in the 2006 primary when he faced the party’s slated candidate.Among the state’s other Democratic Members backing Giannoulias are Reps. Luis Gutierrez, Phil Hare, Bill Foster and Mike Quigley. Reps. Danny Davis and Bobby Rush are supporting Jackson. Rep. Mark Kirk is the likely Republican nominee in the contest. A poll taken in late October for Giannoulias’ campaign showed him statistically tied with Kirk. Giannoulias led 46 percent to 43 percent, a difference within the poll’s 3.5-point margin of error.