Congratulations, Republicans. Now you have your own Obamacare.

Emerging from their caucus meeting in the Capitol basement Tuesday morning, House Republicans were jubilant about their tax bill, which was on course to clear Congress on Wednesday, which it did.

“It’s a total winner,” said Rep. Dave Brat, R-Va. “And I never lie.”

Veteran Rep. Tom Cole, R-Okla., observed: “They’re pretty giddy in there.”

Rep. Neal Dunn, R-Fla., a urologist, announced: “This is good medicine for America.”

And for that prescription, added Majority Whip Steve Scalise, R-La., “you don’t need a second opinion.”

Don’t you?

The deeply unpopular bill has the support of only a third of Americans, most of whom (correctly) perceive that it’s a giveaway to rich people and big corporations. “Any concerns that this won’t translate into a political win for Republicans?” ABC News’s Mary Bruce asked House Speaker Paul Ryan, R-Wis.

“No concerns whatsoever,” Ryan replied. He blamed the bill’s unpopularity on opponents and the media spreading “mistruths” and said opinions will improve when people experience what’s in the bill. “When people see their withholding improving and see bigger paychecks, a simpler tax code,” Ryan said, “results will make this popular.”

Where have I heard this before? Ah, yes, it was March 2010, as Obamacare was about to clear the House. Then-Speaker Nancy Pelosi, D-Calif., said people should look beyond the “controversies” surrounding the bill, to when people experience its “very exciting” benefits. “We have to pass the bill so that you can find out what is in it,” she said.

Obamacare did much of what was advertised, and its popularity grew. But it didn’t do everything that was promised, and anything Americans didn’t like about the health care system became the fault of Obamacare, even if unrelated to the law. Now Republicans are making impossibly high promises, and if anything goes wrong – if the economy doesn’t boom, wages don’t soar and the middle class doesn’t rebound – it will be the fault of this legislation, soon to be labeled “the Trump Tax” by Democrats.

The parallels are eerie. In 2010, as now, lawmakers who drafted the legislation were confident it would be transformational. Then, as now, the legislation passed on an entirely partisan basis, with the opposition complaining about a hurried process and side deals.

Actually, the Trump Tax is in worse shape than Obamacare was. USA Today reported last week that the bill had “the lowest level of public support for any major piece of legislation enacted in the past three decades, including the Affordable Care Act in 2009.” In March 2009, the Quinnipiac poll found opposition to Obamacare exceeded support by 9 percentage points; the latest Quinnipiac poll finds opposition to the tax bill exceeding support by 29 points.

Republicans worked hard to convince Americans that Obamacare was a transfer of wealth from the middle class to the poor. Democrats can now argue, truthfully, that the Trump Tax is a transfer of income from the middle class to the wealthy and big business. Under the law, the middle fifth of American households will see an average increase in after-tax income next year of $930, while the top 1 percent get an average increase of $51,140, according to the Tax Policy Center. The rich even get a greater proportional increase in after-tax income: 2.3 percent, compared with 1.4 percent for the middle class.

While the “forgotten man” who Trump lured with phony populism gets little benefit, the things that bothered the forgotten man about the tax code – a tangled mess of loopholes for businesses, the rich and Wall Street – remain intact.

This will be a “bigger albatross” for Republicans than Obamacare was for Democrats, argues Democratic strategist Jesse Ferguson. “They own the tax code. When you are upset about taxes, you’re going to be upset about the Trump Tax,” he said.

On top of that, Republicans now have claimed ownership of health care. The tax bill kills the individual mandate that underpinned Obamacare, which will leave 13 million additional people without coverage.

Tuesday morning, Ryan declared (falsely) that the bill would “especially” benefit middle-income families. He said it would “bid up” wages, repatriate jobs, provide economic growth of 3 percent a year and create upward mobility.

Maybe he’s right and all those blue-chip economists and the nonpartisan analyses by the Joint Committee on Taxation, the Congressional Budget Office and others are wrong. Maybe growth will dramatically exceed forecasts, millions will enter the labor force and find work, wages will soar and the $1.5 trillion tax bill will pay for itself. But if all that doesn’t happen, the Trump Tax will be blamed.

Dana Milbank is a columnist for The Washington Post. He can be contacted at:

dana.milbank@washpost.com