Near-term energy system decarbonization goals are supported by policy incentives and regulations and interacting with drivers of new demand and planned capacity additions. Long-term decarbonization pathways are often focused on configurations of a transformed system with relatively little emphasis on the intervening transition from near-term approaches to long-term goals. Understanding realistic limitations on deployment and whether and how current approaches support long-term transformation can inform decarbonization pathways in the intervening years. This study designed scenarios to explore decarbonization transitions from existing policy strategies and market conditions to long-term decarbonization goals with a focus on the mid-term interactions of existing regulatory and incentive structures with potential strategies for long-term decarbonization, investigating potential frictions in the hand-off between approaches.