I hear Sen. Maria Cantwell may make a floor speech in the Senate sometime soon to explain her opposition / ambivalence toward the public option for health care reform. I'm looking forward to hearing it, because it's hard to figure out why she wouldn't be in favor of the idea.

Nate Silver crunched the numbers and, allowing for contributions from the health insurance industry, still put the probability that Cantwell would support the public option at 81 percent. Many of her colleagues from Washington State are in favor of the public option. The president has spoken in support of it, and national polling shows Americans overwhelmingly in favor of the idea.

The only thing I can figure is that Cantwell's reluctance relates to her position on the Senate Finance Committee, which is one of two key committees in the Senate working on that chamber's health care proposal. The idea of pushing health care cooperatives instead of the public plan, as Cantwell has been doing, emerged from that committee. In the baroque internal politics of the Senate, it may be smart for Cantwell to keep her head down and support an idea that more senior members of her committee are pushing.

But in the politics of Washington State, it's dumb. The problem Maria Cantwell has always had in this state is that people don't know what she stands for. Her best-known political stance: an achingly slow transformation on the Iraq war, which put her on the wrong side of her political base for a very long time and only added to the sense that she doesn't have a clear political identity. And here she has a chance to lead on an issue that hits every Washingtonian in the pocket book and the heart, health care.

And she's blowing it.

What if Maria Cantwell was the Senator on the Finance Committee who was fighting loudly against the coop compromise? What if she dug in and demanded the committee's bill emerge with a public option intact? She might lose in committee votes and negotiations, but she'd win huge political points back home. Hell, she'd be a hero (or a martyr, which might be even better) in a lot of quarters.

Standing up to Ted Stevens, as Cantwell did a while back, is easy and a political no-brainer. Standing up to centrist Democrats who want to water down real health care reform? That's hard and takes political courage. But the liberal base here in Washington would remember it far longer, and respect it much more, than some tussle with an already-reviled Republican.

It's also the kind of thing that could help Cantwell build up an identity of political conviction—which she doesn't currently have, and would probably be nice to develop by 2012, when she's up for reelection.