The theory in health-care reform has been, thus far, that Democrats need to worry about votes on their right flank. But California Rep. Lynn Woolsey, chair of the 80-member House Progressive Caucus, has been arguing the opposite: that Democrats need to worry about their left flank. The majority of her caucus, she says, will vote against a bill that doesn’t include a robust public option. That’s not been their approach to legislation in the past. But as ardent single-payer supporters, they feel they’ve compromised enough. We spoke this afternoon. A lightly edited transcript follows.