Obama press Wednesday offensive. Obama news conference in Chicago; Plouffe briefs in Washington.

WASHINGTON--Presumptive Democratic nominee Sen. Barack Obama (D-Ill.) faces his traveling national and Chicago local press corps Wednesday at a afternoon news conference in a Michigan Ave. hotel. Before that, Obama will be meeting with a group described as "business leaders" from across the country. No names offered at this time. Meanwhile, in Washington, Obama campaign manager David Plouffe briefs reporters at the Democratic National Committee headquarters. No cameras allowed at the Plouffe session. Plouffe does not want to step on the images from the Obama presser. Once Obama snagged the nomination, he seized control of the DNC operation.