And so it begins. After six years of posturing and futile votes to repeal the Affordable Care Act, Republicans in the Senate have started a process to erase the most important provisions of the health reform law with a simple majority. Millions of Americans are at risk of losing their coverage.

Republican opponents of the health care law insist that it has failed, though it has reduced the number of uninsured Americans to the lowest level in history. They say that it has driven up costs, though health care costs have risen at a much slower pace since 2010 than they did in years past. And opponents promise they will somehow make health care cheaper and more readily available, though after all these years of reviling Obamacare they have yet to offer any serious alternative. The reality is that the repeal-at-all-costs crowd is ideologically opposed to any government role in the health care system, though every other advanced economy in the world has embraced some form of government intervention as the only way to manage costs and ensure universal access.

With a narrow 52-to-48 majority in the Senate, Republicans are seeking to evade a Democratic filibuster by instructing congressional committees to draft a budget reconciliation bill to effectively repeal the tax and spending provisions of the A.C.A., gutting the law and increasing the deficit. The House is expected to easily pass a repeal of the A.C.A., since it has already done so dozens of times.

It should perhaps come as no surprise that zealots would resort to using a budgetary maneuver to fundamentally change national policy. But it is still galling, especially because the Republicans have put forward no coherent plan for what would replace the A.C.A. To cope with that rather glaring omission, leaders like the House speaker, Paul Ryan, and Vice President-elect Mike Pence have discussed repealing the law but then delaying its end — claiming political victory while leaving Mr. Obama’s plan largely in place — to give Congress and the Trump administration more time to come up with a replacement.