“What [Obama] did this week is just going to energize that effort,” Nader promised in an interview with The Daily Caller. “I would guess that the chances of there being a challenge to Obama in the primary are almost 100 percent.”

The only question, he said, is the stature of that opponent and whether it will be either “an ex-senator or an ex-governor” or “an intellectual leader or an environmental leader.”

In approximately a week and a half there will be “another chapter of this effort,” Nader predicted.