Republican Greg Gianforte is up for election tomorrow in a special House race in Montana — and he, allegedly, decided to body-slam Guardian reporter Ben Jacobs after a question about the projected effects of the health care bill Republicans passed earlier this month.

And there’s a way to almost make sense of it. Let’s walk through this:

Jacobs, according to the audio the Guardian released of the incident, asked Gianforte what he thought about the new report from the Congressional Budget Office on the House’s health bill. It’s a pretty innocuous question. (I asked about half a dozen Republican politicians the same question earlier in the day — though none of them had quite the reaction Gianforte did.)

But for Republicans like Gianforte, the answer is complicated. As it turns out, the updated CBO score looks bad — it estimated the number of uninsured would increase by 23 million in the first 10 years and make it much harder for those with preexisting conditions to obtain coverage — barely an improvement on the first draft of the bill Republicans considered.

Gianforte has publicly come out against the American Health Care Act, saying he would not have voted in favor of the version that passed the House, and, as Jacobs pointed out, that he was waiting to make further judgments after the CBO’s score. Privately, Gianforte expressed (in a leaked audio tape) that he was happy the Obamacare repeal and replace process is in motion, which Democrats took to mean that the House passed the bill.

There is no explaining why Gianforte allegedly chose to physically assault Jacobs, but the context around it clarifies just how high the stakes are with health care for Republicans in vulnerable districts.

The Montana special election is proving to be a much closer race than expected in such a deeply red state. And as Vox’s Jeff Stein explained, it’s not only President Trump’s scandal-soaked White House that’s gaining Democrats some ground. It’s policy — and specifically, health care:

Trump may be increasingly unpopular nationally, but Speaker Paul Ryan’s American Health Care Act — which Trump has backed but the conservative vision for which entirely predates his rise — is far more politically toxic. The evidence is mounting in ongoing congressional campaigns. In the upcoming special elections in Georgia and Montana, Democrats’ closing pitches have had far more to do with defending Obamacare than attacking Trump, while the Republicans in those races look to the president for political cover.

Gianforte’s opposition, Democrat Rob Quist — a banjo player with no prior political experience — has been hitting Gianforte hard on health care. Stein explains:

There’s a good reason for Quist to go after the AHCA rather than Trump: The president remains popular in Montana, a state he won by 20 points. (Quist’s opponent, tech millionaire Greg Gianforte, is hugging Trump about as closely as possible.) The Medicaid expansion under Obamacare covered 70,000 Montanans, and the AHCA is polling in the mid-20s nationally, while the approval rating of Obamacare skyrockets.

This is also why House Democrats keep jeering that the American Health Care Act is going to lose Republicans the majority in 2018. (They literally sang "na na na, hey, hey, hey, goodbye" at House Republican as the AHCA passed.)

Democratic and Republican congressional campaign operatives will tell you it’s far too early to know what will actually happen in the midterm elections, but moderate Republicans who are concerned with coverage loss and represent districts that like Obamacare, but still voted for the AHCA, are already showing signs of just how hard this health care vote was for them.

Take Rep. Carlos Curbelo of Florida, who sits in an extremely vulnerable seat in 2018 — he called the new CBO score a "moderate improvement" and said he hopes the progress continues in the Senate.

Other Republicans, like moderate Rep. Tom MacArthur of New Jersey, who was one of the Republicans who helped get the AHCA over the House finish line in May, resigned himself to just questioning the validity of the CBO report. Earlier this week, MacArthur said he would resign as co-chair of the Tuesday Group, the moderate Republican caucus, because they were just too "divided."

The AHCA still has a long way to go — but it’s already on shaky ground. And apparently, as we saw in Gianforte’s case, it means Republicans are getting pestered with questions they don’t know how to answer.