At this point, the debate over whether the American mainstream supports the Republicans’ regressive tax plan is over. Surveys have been consistent for months: the public just isn’t buying what the GOP is selling.

Donald Trump boasted the other day that the more Americans learn about the plan, “the more popular it becomes.” That’s wrong to the point of delusion, as evidenced by every recent independent survey. The latest report on the USA Today/Suffolk University poll noted that the GOP tax plan has the lowest level of public support of “any major piece of legislation enacted in the past three decades.”

With this in mind, we can safely look past the question of whether the plan enjoys public support – it obviously doesn’t – and consider two related points: (1) why the plan is so unpopular; and (2) why Republicans don’t care,

On the first point, despite some recent GOP claims to the contrary, tax cuts tend to be well liked. So why isn’t this one? I suspect it’s partly the result of Republicans misreading the political landscape: as the debate got underway, the public said it didn’t want massive tax breaks for big corporations and the very wealthy. GOP policymakers, rejecting the faux populism behind Trump’s pitch, did the opposite of what most Americans requested (and what the party promised).

It didn’t help that Republicans wrote a hyper-partisan bill, lied about it, and pushed their plan at a ridiculous pace without any real scrutiny – making this look more like a heist than a serious attempt at overhauling the federal tax code.

Common sense suggests that, in a democracy, politicians wouldn’t rush to vote for a dramatic and highly consequential proposal that the American mainstream hates. And yet, here we are. At last count, literally every Senate Republican backs the plan, and when the House votes tomorrow, the number of GOP dissenters is expected to be modest, at best. So why is it, exactly, that the Republican majority is so indifferent toward Americans’ attitudes?

There are a variety of explanations to choose from:

1. Maybe Republicans think the public will be impressed that they finally accomplished something. This may seem hard to believe, but GOP policymakers haven’t had a major legislative accomplishment since George W. Bush expanded Medicare in 2003. It’s possible Republicans expect to benefit politically simply by reaching a goal – even if it’s a goal most Americans don’t like.

2. Perhaps Republicans are trying to make donors happy. A variety of GOP officials have been quite candid about pushing their regressive tax plan because their campaign contributors told them to. If given a choice between listening to the American mainstream and listening to donors, it’s possible some Republican policymakers feel they have no choice but to honor the wishes of the latter.

3. Perhaps this is the GOP’s last hurrah. Mother Jones’ Kevin Drum had an interesting piece the other day, making the case that Republicans are aware of the demographic challenges facing the party – their base is too old and too white in an increasingly diverse country – and they may not control the levers of power again for a while. “That’s why they’re pushing an unpopular tax bill,” Kevin theorized. “That’s why they’re focused like a laser on confirming judges. That’s why they might even take on entitlement reform. They’re going to lose power shortly no matter what they do, so they’re trying to put their stamp on the future while they still have the chance.

4. Maybe “wingnut welfare” is on Republicans’ minds. It’s a provocative idea, but Vox’s Ezra Klein suggested the other day that it’s possible many Republicans, looking at the polls, expect to lose at the ballot box quite soon, so they’re “trying to please the donors and lobbyists who can give them jobs after they’re voted out.” (For more on the general idea, the New York Times’ Paul Krugman explained his “wingnut welfare” thesis in 2015.)

5. Do Republicans think they’ve immunized themselves from all backlashes? This is largely the opposite of Kevin Drum’s argument, but I’ve heard some suggestions that GOP officials no longer care what voters think because they believe they’ve successfully shielded themselves from public attitudes.

Thanks to a combination of gerrymandering, voter-suppression techniques, and a seemingly endless amount of campaign contributions, which can be used to tell voters the GOP’s tax bill is the opposite of what it actually is, Republicans may have convinced themselves they can win elections, en masse, whether voters approve of their records or not. They can do as they please because, in their minds, the consent of the governed is now little more than an annoying, irrelevant detail.

And while those explanations have their proponents, I’m partial toward 6. Republicans actually believe their own talking points. My best guess is that the vast majority of GOP lawmakers simply believe that the American mainstream is made up of cranks and fools who fail to understand the awesome power of trickle-down economics. Republicans are ignoring public opinion because, in their imaginations, they’ll ultimately be rewarded by voters who will soon discover that cutting taxes for the wealthy and big corporations will produce broad economic prosperity – just like in Kansas.

Once regressive, poorly-thought-out tax cuts work wonders, we’ll all collectively apologize for our silly assumptions and thank our Republican betters for ignoring the American public – not to mention economists, the JCT, the CBO, business leaders, labor unions, all of modern history, et al – and creating an economic utopia.

That, I suspect, is the Republicans’ real rationale.