The US Postal Service has a long-standing policy of only honoring deceased persons on stamp. That's a good rule.
As for Obama--outside of the Chicago area--he's not that popular in Illinois.
From Fox St. Louis
Several Illinois lawmakers are calling for former President Barack Obama's birthday to become a state holiday. The Chicago Tribune reports that, if the law is passed, August 4th would become the state's 13th official day off.As for the Reagan holiday in California, that began after he announced that he was suffering from Alzheimer's disease and left public life.
The legislation was proposed by Democratic state Representatives Andre Thapedi and Sonya Harper. Thapedi tells the newspaper that California instituted a similar state holiday for Reagan while he was still alive. But, that holiday did not call for a state shutdown. He notes that the state shut down and bank holiday are, "important to me and to my constituents."
Gov. Bruce Rauner’s office tells the Chicago Tribune that they are reviewing the
"Obama Day Bill."
Illinois is beyond broke. It does not need another day to pay state employees for not working.