In a moment Tuesday that was almost surreal, Senator John McCain, back from surgery and a brain cancer diagnosis, said that Republicans were making a big mistake with their partisan approach to health care, among other subjects. “We have been spinning our wheels on too many important issues because we keep trying to find a way to win without help from across the aisle,” he said. The substance of what he said accurately described the fecklessness of his party. What made it surreal was that only moments earlier he had voted along with almost every other member of his party to endorse Mr. McConnell’s obsession; Senators Susan Collins and Lisa Murkowski were the exceptions.

There are three main proposals before the Senate. On Tuesday night the Senate failed to muster enough votes to advance one of those: the Better Care Reconciliation Act. That bill would have gutted Medicaid and slashed insurance subsidies, taking coverage away from about 22 million people, according to the Congressional Budget Office. Another, the Obamacare Repeal Reconciliation Act, would eliminate important parts of the law without a replacement, stripping 32 million Americans of health insurance. The third option is called “skinny repeal” because it would leave much of the A.C.A. in place but eliminate one of the law’s taxes and the mandates that individuals buy insurance and that employers offer it to their workers. That plan could increase the uninsured population by up to 15 million. It would also cause insurance companies to raise premiums by 20 percent.

The details are complicated, but most Americans understand that these proposals would be incredibly cruel and needlessly devastating, which is why polls have shown that few people support the partisan repeal effort. A recent Kaiser Family Foundation poll found just 28 percent supported the Senate bill to repeal and replace the A.C.A., while 71 percent wanted Republicans and Democrats to work together to improve the law.

Republicans seem oblivious to those concerns, and to the danger that voters who lose access to health care could retaliate at the ballot box in the 2018 and 2020 elections. Some lawmakers may have decided that voters will in fact reward them for living up to their promises to repeal Obamacare, and that because actual repeal would be delayed two or more years, they will pay no price. Still others may have voted yes because they were afraid of losing primary elections to challengers further to the right than them.