The American Health Care Act is a misnamed, regressive tax-cut bill meant to fool you into thinking its primary purpose is improving the health care system. But the incredible cruelty of the Republican legislation didn’t become clear until Monday, when the Congressional Budget Office—led by a conservative economist whom House Speaker Paul Ryan personally selected—estimated it would undo nearly all of the coverage gains we’ve seen under the Affordable Care Act, creating human tragedy on a scale far greater than even pessimistic analysts imagined.

Republicans claim that Trumpcare is a simple matter of keeping their promise to repeal Obamacare. But if keeping promises were their guiding principle, they wouldn’t be ignoring the other ones they and President Donald Trump made: to preserve coverage gains and lower costs, and in doing so take care of people on the flip side of repeal. They are instead attempting to break those promises as swiftly and completely as possible, and at the expense not mainly of liberal Obamacare supporters, but of the very voters most inclined to have believed the lies. The swindle is greater than even we imagined.

Amid all the deception, Republicans have been fairly forthright about why they’ve made Obamacare repeal their first priority: It is so that they can ultimately reform the tax code on a permanent basis. Congressional budget rules exempt certain tax and spending bills from filibusters, but only if they don’t incur long-term deficits. It is very hard to cut taxes regressively and permanently without either building a partisan supermajority or figuring out a way to pay for the tax cuts. As George W. Bush–era Republicans learned, if you use the budget rules to pass a large deficit-financed tax cut, the tax cut will eventually expire.

Repealing Obamacare offers Republicans a way out of that trap, because it pairs eliminating (or indefinitely delaying) all of the ACA’s progressive tax increases with gutting the financial assistance the law provides to help millions of people afford care. It’s spoken of as “Obamacare repeal,” but it’s equivalently a large tax cut for the rich paid for by taking insurance away from the working class and poor. This filibuster-proof tax cut, in other words, would be permanent. And by reducing the revenue baseline, Republicans could make separate, deficit-neutral reforms to the tax code without having to sacrifice their goal of reducing the top marginal rate: all of the iniquity of the Bush tax cuts, without the automatic sunset.

This strategic imperative revealed something important about GOP priorities: that tax cuts outrank health policy in the Republican policy schema. But using Monday’s CBO report, we can sketch these priorities with greater precision, and the picture that emerges is vicious.