THE BACKUP PLAN…. No one can say with confidence what voters in Massachusetts will do tomorrow, or how members of Congress will react to the results. But it’s hardly a stretch to suspect that health care reform, Ted Kennedy’s life’s work and a policy goal sought for decades by lawmakers from both parties, would suffer a devastating blow if Scott Brown (R) comes out on top.

Of course, if Martha Coakley (D) wins, reform becomes a near certainty. But with the outcome in Massachusetts very much in doubt, there was quite a bit of talk over the weekend about the backup plan — what Democratic policymakers would do if Bay State voters ignore their values and give Senate Republicans the votes needed to block the legislative process for the rest of the year.

At this point, the approach generating the most attention is the most straightforward — the House passes the Senate bill, sends it to the president for his signature, and Congress moves on to other issues while making changes to the health policy in the budget bill. This, the NYT, is the “favored fallback” among some Democratic leaders.

Of course, we know the Senate bill isn’t exactly popular in the House, especially among the more progressive members of the caucus. Left with limited alternatives, and facing the this-or-nothing possibility, would they accept it anyway?

Jonathan Cohn ponders the likelihood, emphasizing the fact that the entire health care reform debate could end as quickly as this week — the House passes the bill by Friday, the president puts his signature on it soon after.

Would House Democrats go along? It’s hardly a given. Centrists, many of them as ambivalent about reform as their Senate counterparts, would be tempted to use Coakley’s defeat as an excuse for voting “no.” Liberals, meanwhile, would chafe at supporting a bill that includes so many unpleasant compromises.

But there are good substantive reasons why both sides should be willing to vote “yes.” And there are some good political reasons, as well.

For centrists, the substantive reason is that the Senate bill is, in most respects, closer to what they originally wanted anyway. Centrist Democrats skittish about the House bill typically complained that it was just too much — too much spending and too much regulation. But the Senate bill has less of both. […]

[T]he arguments for voting for the final House-Senate compromise are just as relevant here: Flawed though it is, the Senate bill would represent a monumental policy achievement, one that would benefit tens of millions. And House Democrats could always try to fix the bill later on — maybe even quickly, if they can take advantage of the reconciliation process, which would remain available.

Stay tuned.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.