ABC News’ Matthew Jaffe reports: Illinois Democrat Roland Burris today bid farewell to the Senate, leaving the upper chamber of Congress without any African-American lawmakers for the next two years. “This is simply unacceptable,” Burris said in a speech on the Senate floor. “We can and we will and we must do better.” Burris is set to be replaced by newly-elected Republican Mark Kirk later this month. With senators set to leave town in the coming days for a week-long Thanksgiving break, Burris today took the chance to give some final remarks. His departure means there will be no black senators for the next two years, a fact that he lamented this morning. “Our government hardly resembles the diverse country it was elected to represent,” he said. Burris’ exit caps a tumultuous 22-month run that began in controversy. He was appointed by disgraced Illinois Gov. Rod Blagojevich to fill President Obama’s Senate seat after the 2008 elections even as Blagojevich was accused of trying to sell the seat. But Burris accepted the appointment, overcame a Senate Ethics Committee reprimand, and withstood calls for his resignation to serve for nearly two years.