Reason: Blanche Lincoln  will vote yes in procedural votes in an effort to conceal her real intention. For example, the cloture vote, which ends the debate, will probably be the critical vote, but it's not the vote for final passage. However, it's the one to watch. Blanche could vote yes on cloture but no on final passage, and try to have it both ways. The Senate leadership may not need her vote for final passage, only for cloture.

Nice trick if she can make it work and fool everybody back home.

Other commentators see her ruse as well.