A hybrid-electric propulsion system, comprising: a power converter; and a propulsor, comprising: a gas turbine engine having a shaft and one or more bearings supporting the shaft; and an electric machine electrically coupled with the power converter and including a stator assembly and a rotor assembly, the rotor assembly having a rotor and a rotor connection assembly, the rotor connection assembly operatively coupling the rotor with the shaft, the rotor connection assembly having an insulated joint for interrupting common mode electric current from flowing between the rotor and the shaft, wherein the rotor connection assembly has a rotor hub and a rotor connection member, the rotor hub being connected to the shaft and the rotor connection member being connected to the rotor, the rotor hub and the rotor connection member being mechanically coupled with one another by the insulated joint, and wherein the insulated joint comprises a hub flange of the rotor hub, a connection flange of the rotor connection member, a bolt extending through the hub flange and the connection flange, and one or more insulative members (333, 335, 337) electrically isolating the rotor connection member from the rotor hub. a power converter; and a propulsor, comprising: a gas turbine engine having a shaft and one or more bearings supporting the shaft; and an electric machine electrically coupled with the power converter and including a stator assembly and a rotor assembly, the rotor assembly having a rotor and a rotor connection assembly, the rotor connection assembly operatively coupling the rotor with the shaft, the rotor connection assembly having an insulated joint for interrupting common mode electric current from flowing between the rotor and the shaft, wherein the rotor connection assembly has a rotor hub and a rotor connection member, the rotor hub being connected to the shaft and the rotor connection member being connected to the rotor, the rotor hub and the rotor connection member being mechanically coupled with one another by the insulated joint, and wherein the insulated joint comprises a hub flange of the rotor hub, a connection flange of the rotor connection member, a bolt extending through the hub flange and the connection flange, and one or more insulative members (333, 335, 337) electrically isolating the rotor connection member from the rotor hub. a gas turbine engine having a shaft and one or more bearings supporting the shaft; and an electric machine electrically coupled with the power converter and including a stator assembly and a rotor assembly, the rotor assembly having a rotor and a rotor connection assembly, the rotor connection assembly operatively coupling the rotor with the shaft, the rotor connection assembly having an insulated joint for interrupting common mode electric current from flowing between the rotor and the shaft, wherein the rotor connection assembly has a rotor hub and a rotor connection member, the rotor hub being connected to the shaft and the rotor connection member being connected to the rotor, the rotor hub and the rotor connection member being mechanically coupled with one another by the insulated joint, and wherein the insulated joint comprises a hub flange of the rotor hub, a connection flange of the rotor connection member, a bolt extending through the hub flange and the connection flange, and one or more insulative members (333, 335, 337) electrically isolating the rotor connection member from the rotor hub.