The U.S. Capitol building. (Marlon Correa/The Washington Post)

There is an opportunity for one or two Republican senators to be 21st-century Profiles in Courage. A senator who stands up to his or her party and casts the decisive vote against the Cassidy-Graham health legislation will be seen by history as a hero.

Cassidy-Graham is the cruelest and most misguided piece of consequential legislation proposed so far in the 21st century. It is far worse than the “repeal and replace” bills that Congress has so far voted down. Cassidy-Graham is much more dangerous than previous bills, both because it goes further in eliminating critical parts of the Affordable Care Act and because it savages the pre-ACA Medicaid safety net.

Start with what Cassidy-Graham does to the ACA, which established the landmark principle that health insurers could not discriminate against sick people or those with preexisting conditions. This idea was endorsed even by President Trump and preserved in earlier legislation. Cassidy-Graham restores the ability of private insurers to exclude people with preexisting conditions. It also knocks out the entirely reasonable provisions of the ACA requiring that insurance cover mental health, substance abuse treatment and maternity. And it eliminates the funding that went to expand coverage under the ACA through Medicaid expansion and tax credits, instead providing a block grant to states that is insufficient to replace it before ending altogether in 2026.

Maybe even worse than what Cassidy-Graham does to the ACA is what it does to the underlying Medicaid program. Rather than maintain the federal guarantee to fund a share of Medicaid costs currently in place, the bill would convert the Medicaid program to a “per-capita cap” — with cuts that grow deeper over time. One consulting firm, Avalere, estimated that the cuts to Medicaid outside of the ACA would be over $1 trillion by 2036. That would inevitably require states to make deep cuts to coverage and services for the seniors in long-term care, people with disabilities and families with children who use the program.

I don’t understand how those supporting Cassidy-Graham live with themselves. People will die and they will be responsible. And what will follow ultimately after the backlash comes will make the ACA look like a libertarian dream. If ever there was a moment for a courageous Republican to step up, this is it.