"There's a growing investment in the farm team by a lot of national groups that are thinking about what's happening in the states a lot more," said Adam Green, co-founder of the Progressive Change Campaign Committee. (His pick for 2016: Elizabeth Warren -- who, he notes, would by that time have the same amount of Senate experience as Obama had in 2008.) It's a matter of quality as well as quantity, he said. "We need to train people to fight so that they are actually fighters when they get to Congress, not just votes."
These efforts are gaining steam, said Gloria Totten, president of Progressive Majority, whose mission is to elect progressive candidates to statehouse and congressional seats. The group has trained 234 candidates who are running this cycle. But as for who might succeed Obama, she drew a blank: "Yikes," she said.
Many on the left defend the lack of readily apparent future presidential candidates by saying they're building a movement, not a cult of personality. "I see the progressive movement as the rising star in the Democratic Party," Rep. Keith Ellison of Minnesota said in an interview. "I'm very reluctant to identify charismatic individuals. I know they excite us and we want to know about them, but the truth is, there will be excellent vessels to carry the message, but it's the message [that matters], you know what I'm saying?"
Ellison did acknowledge that Republicans have done a better job bringing fresh blood into their ranks, especially in Congress. "Here's the reality," he said. "Democrats were out of power for a long time, so once they finally get in the majority, they don't want to move. Quite frankly, sometimes you have leaders who have been around quite a long time." He pointed to the dynamic young trio of Republican House leaders -- Majority Leader Eric Cantor, Majority Whip Kevin McCarthy and Budget Committee Chairman Paul Ryan, all under 50 -- as counter-examples: "It might not be a bad idea to look at what the Republicans are doing."
Democrats, on the other hand, are still led in the House by 72-year-old Nancy Pelosi. "Nancy Pelosi is one of the most vigorous people I've ever met in my life -- I'm not making an age argument," Ellison said. "There are occasions, though, when we need to understand for the continued viability of our party, our values, it's all right to let someone else come in."
I pressed Ellison for names for 2016, and he thought for a moment. "If we can get Elizabeth Warren through in Massachusetts, she could end up being a presidential candidate," he finally said. "She's super."
* Disclosure: Michael Bennet is the brother of the editor of The Atlantic, James Bennet.