To listen to the Democrats, the American middle class will be lucky to survive the Republican tax bill.

Nancy Pelosi calls the bill “monumental, brazen theft from the American middle class,” and that’s one of her more restrained comments. Per Pelosi, the bill is an affront to the Founding Fathers, veterans, children and all that’s good and true in America.

She constantly charges that the bill “raises taxes on 86 million middle-class households” and “hands a breathtaking 83 percent of its benefits to the wealthiest 1 percent of Americans.”

This is a rhetorically potent line of attack that the polling suggests has made considerable headway. It just isn’t remotely honest. The Republican bill is, every factual analysis agrees, an across-the-board tax cut.

Pelosi’s seemingly damning factoids come from the year 2027, an odd date to focus on, since it’s not when the bill goes into effect, but when part of it lapses. In about 10 years, many of the tax cuts on the individual side expire. This means that the middle-class tax cuts go away, which Pelosi portrays as a Republican plot to loot the middle class.

It’s a very strange argument against passing a bill to say horrible things will happen once the legislation no longer fully applies. This is more logically a case for extending the bill than for blocking it. Indeed, it’s almost certain the middle-class provisions would eventually be preserved. (This is one reason Republicans were willing to let the individual tax cuts sunset and not the corporate tax cuts.)

If Pelosi were being more scrupulous, she’d say, “If 10 years from now, Democrats for some reason don’t agree with Republicans to extend the middle-class tax cut — then they will disappear and it will be shame on us.”

What is, by the way, this looming middle-class wasteland in 2027? Pelosi is relying on the liberal Tax Policy Center for her figures. As that outfit puts it, “on average, in 2027 taxes would change little for lower- and middle-income groups.” Oh.

According to the TPC, the lowest quintile of “tax units” would see, on average, a $30 tax increase in 2027. The second quintile would see a $40 increase. And the middle quintile a $20 increase.

There’s a reason Pelosi doesn’t want to focus on the numbers when the tax bill she so vociferously opposes is fully in effect. In 2018, 80.4 percent of tax units get a tax cut, averaging $2,140. A grand total of 4.8 percent will see a tax increase. The small percentage of people who will get a tax increase is disproportionately tilted toward the top of the income scale.

There isn’t really debate over the broad contours of the bill. According to the analysis of the Joint Committee on Taxation, the average tax rate goes down for every income cohort in 2019, and the share of federal taxes paid by millionaires will rise slightly to 19.8 from 19.3.

It’s true upper-income people get a bigger tax cut in terms of absolute dollars than anyone else. This is going to be the case for any across-the-board tax cut for the simple reason that the wealthy tend to pay more in taxes than anyone else.

The Manhattan Institute’s Brian Riedl points out, “The bottom 80 percent of families currently pay 33 percent of all combined federal taxes, yet will get 35 percent of the tax cuts. By contrast, the top 1 percent currently pays 27 percent of all federal taxes, but will get just 21 percent of the tax cuts. This means the share of all federal taxes paid by upper-income earners will slightly rise.”

The tax bill is hardly invulnerable to criticism. Corporate tax cuts aren’t popular, but they are pro-growth. There used to be a bipartisan consensus — including from Presidents Barack Obama and Bill Clinton — that we needed corporate tax reform.

Then there’s the deficit. Republicans can fairly be taken to task for budget gimmicks (like the expiration of the individual tax cuts) that squeeze a much bigger tax cut into a $1.5 trillion, 10-year window.

All things being equal, economic growth will diminish some of the revenue loss. But the bill could’ve been smaller and added less to the deficit.

This wouldn’t matter so much if Republicans had a politically plausible strategy to reduce the growth of entitlements. They don’t, and the same Democrats complaining about red ink now will fight savagely to preserve the automatic spending that contributes most to the US debt.

It’s impossible to say how the tax bill will play in the midterms. What is certain is that contra Pelosi, the middle class will emerge intact, and with a lower tax bill.

Twitter: @RichLowry