Arlen Specter became the 19th Senator to sign onto the public option through reconciliation letter to Harry Reid yesterday, tweeting "I'm proud to sign Sen. Bennet's letter. I support a public option to lower health costs and keep insurance co's honest."

Nearly 20 Senators, including representation from leadership in the person of Chuck Schumer, during recess is a pretty significant accomplishment. It signals, at the very least, a recognition that the public option is indeed popular. But on top of that, it's the recognition that reconciliation is the only to get this accomplished, and that getting this passed is going to be key to having a supportive and active base in this election.

It's taken months and months of progressive messaging to make the point that the White House is now pushing:

White House aides have begun to make the case that passing a bill through reconciliation isn't an extraordinary move, noting that it was used frequently under President George W. Bush. Mr. Obama also argued Friday that recent price increases by insurance companies demonstrate the need for such an overhaul.

But we're there now. Keeping the momentum going is, in part, going to depend on the message the White House and leadership in the House and Senate gets from rank and file members. Which, in turn, depends on the message they get from us: fix it and pass it. They keep hearing that polling shows the base wants healthcare reform done, and that the public option remains popular with everyone except the third of voters who will be opposed to anything done while Obama is president.

They perhaps know that intellectually, but they need to hear it personally. They need to hear from their constituents--and particularly all the people who they regularly rely on not just for votes, but for volunteer action and donations--that we have an expectation. We want healthcare done, and done right. We don't want platitudes and empty promises. If they mean it, they need to fight for it. The message needs to be delivered to Pelosi, Reid, and Obama directly from us, but also from rank and file congressional members. The best way to achieve that is to follow nyceve's example, and make a lot of noise.

Update: Sen. Menendez has also now signed on. With Reid's stated support, that makes three out of four in Senate Dem leadership. Where's Durbin?