A handful of centrist senators from both parties met this morning to discuss withholding their votes to send a healthcare overhaul bill to the floor if it includes provisions they disagree with, such as a public option. Their concerns might undermine Democratic leaders’ hope of convincing wavering members to vote to avoid a filibuster and allow limited debate whether or not they agree with the overhaul legislation. “I’ve not said that my cloture vote is a given, and I’d be very concerned about a cloture vote if I believe the underlying bill is something I can’t live with,” said Sen. Ben Nelson, D-Neb.