“He said we [as Democrats] shouldn’t be afraid of big, bold ideas — but also need to think in the nitty-gritty about how those big, bold ideas will work and how you pay for them,” said one person summarizing the former president’s remarks…

People in the room, who spoke on the condition of anonymity to describe the evening, said Obama’s cost warnings weren’t deficit-scolding, per se. Rather he argued that voters care about the costs associated with policies and that Democrats should be ready to answer questions about how they will pay for an idea while making big promises to constituents.

Obama gave the example of taxes: Even a liberal, he argued, could be repelled from supporting a liberal policy if it’s accompanied by a major tax cut to their own bottom line.