Sen. Mark Warner , Senate , surprised political world with her decision not to run again . `` I think she lost hope , '' a fellow R-Maine Republican said . Snowe is the latest in a string of Senate centrists to announce retirement . Harry Reid 's hand . '' Despite departures , some centrists remain including Sen. Olympia Snowe , Republican .
Sen. Mark Warner , Senate , surprised political world with her decision not to run again . `` I think she lost hope , '' a fellow R-Maine Republican said . Snowe is the latest in a string of Senate centrists to announce retirement . Despite departures , some centrists remain including Sen. Olympia Snowe , Republican .