The public option saves money, according to the CBO:
In a bid to wrangle concessions from the Blue Dog Coalition on healthcare reform, House leaders Thursday released CBO estimates for liberals' preferred version of the public option that show $85 billion more in savings than for the version the Blue Dogs prefer. [...]
In total, a public plan based on Medicare rates would save $110 billion over 10 years. That is $20 billion more than earlier estimates, a spokesman for House Speaker Pelosi said.
Blue Dogs claim to be fiscally responsible. Then they ought to be supporting the public option. By refusing to do so, they're in favor of wasting $85-$110 billion in taxpayer money.
I think we have a strong argument here for any progressive primary challengers. Nail the Blue Dogs on fiscal irresponsibility.