An aging U.S. senate coud be a threat to democrats. According to politico, some US senators from key states are quite old, which could prove a challenge to democrats during elections in two years. Retirements rumors are swirling around senators like Democrat Diane Feinstein and republican Orrin Hatch. So far no incumbent has announced plans to leave. Republicans took control of the senate this year and hope to widen their advantage in 2018.