In an interview with TPMDC, Joe Sestak has started to trace out his message against Arlen Specter. Based on nothing but my own subjective appraisal, I think it has real promise: Specter can't be trusted.
A few weeks ago, Sestak told me that Specter would need to prove himself a reliable Democrat on key issues if he wanted to avoid a challenge, but ultimately he decided that Specter just can't be trusted.
"[W]hen you see someone who has voted so consistently with President Bush--I think it's four out of five times--that voted on issues that have been very instrumental in terms of harming our national security...or for the economic policies of the Bush administration.... That raised even graver doubts about how is he going to now forsake those kinds of beliefs in any consistent way."
Then again, I wonder if this message is enough. Many voters simply assume that politicians are spineless, so a "flip-flopping" charge doesn't mean much to them. Others might simply like that he flipped, because he now holds their position. So, the "trust" charge is going to have to connected to something more concrete. Something more like: can you really trust Arlen Specter to fight for you on health care and creating jobs?
What message do you think Sestak should use against Arlen Specter? Let's start brainstorming in the comments.