We can't know, at this point in time, what the Senate will ultimately decide about health care reform; to paraphrase the poet Robert Frost, the Democrats have promises to keep but miles to go before they sleep. All we can say for sure is that there will be much tossing and turning between now and year's end.

But thanks to the House action on Saturday night - when, for the first time ever, a congressional chamber decided to give Americans the same kinds of health care guarantees that are common everywhere else in the advanced western world - we finally have some actual voting stats that can be viewed through a political filter.

So let's do it, because there's a good story about the No-voting Democrats...and why their votes won't protect them from Republican attack in 2010. In the political game, it's tough to get attack insurance; in this episode, they've been denied coverage.

Since the House Republicans were virtually united in doing what they do best - saying No, doing squat about health reform - the prospects for passage hinged on the decisions of the 49 Democratic lawmakers whose constituents are generally loyal to the GOP. Those 49 Democrats represent congressional districts that supported John McCain in 2008. On the eve of the Saturday health care vote, not surprisingly, those Democrats got a pep talk from President Obama.

By my tally, 31 of those 49 Democrats opted to side with the Republicans and vote No on health reform. And looking at the stats another way: Of the 39 House Democrats who ultimately voted No, 31 hailed from Republican districts.

It wouldn't be accurate to imply that all the 31 red-district Democrats voted No just for reasons of political survival. Some of them are "Blue Dog" fiscal conservatives who sincerely feel that the reform package is too costly; three of them (from districts in Virginia, West Virginia, and Tennessee) didn't even have Republican opponents in 2008, thus enabling them to garner roughly 100 percent of the vote. But clearly, many of these Democrats voted No in part because they sought to innoculate themselves from Republican attack in 2010, to prevent the GOP from hanging the reform vote around their necks in front of their GOP-leaning voters.

Just as interestingly, however, is the tally in reverse - the fact that 18 of those 49 red-district Democrats stuck with Obama and voted Yes on health reform. Indeed, it can be argued that those 18 (including Pennsylvanians Chris Carney and Kathy Dahlkemper) ultimately smoothed the path to passage.

There's little doubt that some of those 18 Democrats sincerely believed in the reform package, notwithstanding the general political composition of their districts, and voted Yes accordingly. But it's likely that some were swayed in part by something that Obama reportedly said to them on the eve of the vote. Let's just say that it was wise political advice. Obama told the red-district Democrats that it would be nuts to think that a No vote on health reform would somehow protect them from Republican attacks in the '10 elections; he said that the Republicans would go after them next year anyway, regardless of how they voted.

True that. The GOP's modus operandi is obvious by now. Early in this decade, scads of Democrats - hoping to protect themselves from Republican attack, and anxious to innoculate themselves with the folks back home - voted in the House and Senate for the Bush tax cuts and the ruinous '02 Iraqi war authorization resolution. Their bipartisan gestures didn't protect them at all; under Karl Rove's direction, the Republicans went after them anyway in the '02 congressional elections.

And next year, it's similarly a cinch bet that the Republicans will target most of the 31 red-district Democrats who voted No on health reform. Even though those Democrats voted with the GOP, they won't get a pass from the GOP attack team, especially if the GOP judges those districts to be winnable. If a red-district Democrat essentially says, "hey, don't blame me, I voted No on that health reform package," the Republican challenger will simply say, "So what if he voted No? The only way for voters to send Nancy Pelosi a message is to defeat him. No Democrat in Congress can hide. My opponent is a Democrat who was powerless to stop the extreme liberal left-wing Democrat plan for a government takeover of our health care system, an assault on the timeless virtue of American liberty that will place Americans' personal medical decisions in the hands of faceless bureaucrats."

Virtually all the overheated phrases in that latter sentence are lifted directly from Republican statements released over the past 48 hours. (Last I heard, our personal medical decisions have long been in the hands of faceless insurance company bureaucrats.) These phrases give us a flavor of what Republicans are rhetorically planning for 2010.

Most of those No-voting Democrats are likely to realize, sooner rather than later, that they have failed to insure themselves against attack. They have been denied coverage, simply because they are Democrats. Call it their pre-existing condition.