The 25 or so Republican conservative congressmen who are saying they will vote against President Donald Trump's health care bill hold the fate of the Trump presidency in their hands.
Battered by a biased media and harassed by attempts to link him to Russia, Trump needs to produce a solid record of achievement to stay viable. And once he loses viability, it's almost impossible to get it back.
Nothing is so identified in the public mind with the Republican Party as its opposition to Obamacare. If President Trump fails to pass his plan to replace the Affordable Care Act in the House, he will be badly wounded.
He will be regarded as ineffective as well as unreliable. It will be a long, long four years.
Conservatives have made a number of good points about the Trumpcare legislation. It is too generous to Medicaid recipients. It would cement in place the vast expansion of Medicaid that Obama authorized.
There is no rollback to the list of mandated services that must be included in insurance policies — a failure that drives up premiums, resulting in the Congressional Budget Office's predictions of fewer people insured and of higher deficits and costs.
But these elements will most likely be added to the bill when it goes to the Senate. There, it will become clear that Trump has no prospect of getting 60 votes.
The stonewalling Democratic opposition makes that point abundantly clear. Faced with this barrier, the Senate Republican leadership will have no alternative but to either overrule the parliamentarian and pass the entire package with 50 votes or to eliminate filibusters entirely.
Once this logjam is broken, all of the conservative amendments become possible, particularly those that limit or eliminate the mandatory list of services.
It is fear of the Senate that stays the administration's hand and stops it from including these changes in the House bill. But once these obstacles are clearly not going away, the Trump administration and the Senate majority will have no choice but to overcome them.
In the meantime, rejecting the current bill in the House cripples Trump at the very time that he needs maximum support and power. The resulting image of dysfunction will do more to cost individual conservative members their seats than any backlash over the limitations of the current House health care bill.