Congressional Progressive Caucus losing its nerve?

I signed Alan Grayson's petition for no cuts to Medicare, Medicaid or Social Security, and posted a link for it on the blog. But according to this story 75% of the Congressional Progressive Caucus (CPC) have yet to sign a letter pledging not to cut these vital programs. What's up with that? The list of the cowards is here. I've championed the CPC as an example of how true progressives represent the people and not special interests. But on this one there is no excuse. Please consider contacting these deadbeats if they represent you and let them know your opinion. Thanks.