As the blame game launches on the Senate health-care bill, there is perhaps no more illustrative example of President Trump's role in the negotiations than this:

It's Monday evening. A second version of the Republicans' bill is in danger of flatlining. Two GOP senators are opposed to it, almost a dozen have expressed serious concerns with it, and if just one more Republican opposes it, it's game over for an Obamacare overhaul.

Trump is having dinner at the White House with seven Republican senators to talk health care. Of the seven, only Steve Daines (Mont.) had publicly expressed concerns about the bill.

As they dined, fellow Republican Sens. Mike Lee (Utah) and Jerry Moran (Kan.) were crafting statements that would implode the GOP's attempts to unravel Obamacare for the foreseeable future.

That Trump was completely blindsided by the news that the bill was effectively dead shows, despite his rhetoric on Twitter and in public appearances, how unable or unwilling Trump has been to influence the outcome of the health-care debate.

Lee and Moran announced, together, on Twitter around 7:30 p.m. Eastern time that they couldn't support the bill because it didn't go far enough to repealing Obamacare.

That would make four “no's” — two more than the bill could afford. Just like that, the Republicans' second attempt to undo Obamacare died. And the person arguably in charge of the Republican Party and its platform — Trump — was caught off guard by this, as he was dining with senators who actually support the legislation.

Here's Trump, speaking briefly to reporters Tuesday:

Republicans in Washington were dumbfounded that, with the GOP health-care bill on the line, Trump decided to spend his time eating with allies rather than trying to win over adversaries. And it blew up in his face in the most spectacular way.

“The senators who announced their opposition last night were two that have been most vocal about their hesitation to McConnell’s efforts for weeks,” said a Republican who spoke on condition of anonymity to speak candidly about the president's strategy. “It hasn’t been a secret who those people are, and those are who the president should be wining and dining. To be spending valuable time with reliable ‘yes’ votes doesn’t seem to make much sense.”

Trump wasn't the only one surprised by the sudden death of the Republican health-care bill. Sen. John Cornyn (R-Tex.), whose job as the No. 2 Senate Republican is to count votes, said he was caught off guard by the timing of Lee and Moran's announcement.

But Cornyn has played an active role in at least trying to sell these senators on the legislation. Politico called him “Obamacare repeal's top salesman.”

Cornyn was one of the attendees at the Monday White House dinner, along with Sens. Daines, Lamar Alexander (Tenn.), Roy Blunt (Mo.), James Lankford (Okla.), Richard C. Shelby (Ala.) and John Thune (S.D.).

Unlike Cornyn, Trump never expressed more than a passing interest in getting the bill passed. Sure, he tweets about how bad Obamacare is. And he tweets veiled threats at some Republicans who aren't cooperating. But he hasn't made any concrete lobbying effort to win over those senators. He hasn't gone out of his way to explain why Americans should support the bill, other than it's not Obamacare. Not coincidentally, the bill is really unpopular.

In fact, on Tuesday, he raised eyebrows by trying to spin the bill's loss as a personal win.

We can look all the way back to this spring, when House Republicans were trying to pass their measure unraveling Obamacare. Trump wasn't a central figure in that fight, either.

As House Speaker Paul D. Ryan (R-Wis.) was about to face an embarrassing setback on the legislation, Trump went to Michigan to promote his administration's reconsideration of fuel efficiency standards. He didn't mention health care once. (The same day, we counted almost 60 Republican House members who had serious concerns about the bill, more than enough to sink it.)

There are several reasons Republicans control all of Washington and have failed to deliver on their singular promise, to repeal Obamacare.

But Trump's total lack of interest in selling the legislation — and seemingly ham-handed efforts to inject himself in the debate — is perhaps Republicans' biggest struggle of all. They don't have a president who seems to understand how to close a deal in Washington.

Robert Costa contributed to this report.