The Post editorial: Sadly, the GOP is relying on a legislative gimmick — the sunset provision — in tax plan.

When we endorsed the GOP tax reform plan two weeks ago, we had the basic expectation that Republicans would be intellectually honest in their pursuit of a lower corporate tax rate and a more fair individual tax code.

Sadly, we assumed too much. Instead of making the hard decisions when looking to make the proposed tax overhaul feasible under federal budget needs, Republicans turned to a tried-andtrue legislative gimmick — the sunset provision.

Unable to keep their tax giveaway within the massive limits of $1.4 trillion over a decade, Republicans amended the House plan to make many of the proposed reductions in individual tax rates temporary.

The result is that while in calendar year 2019 Americans would pay on average 7.4 percent less on their federal income taxes, by 2027 all of that net benefit would be eliminated. Worse, because the policies Republicans targeted to phase out are those that benefit lower-income Americans more, the increase would be borne on the backs of the poor.

According to the Joint Committee on Taxation, in 2027, Americans making between $20,000 and $30,000 would see an unacceptable 25 percent increase over what they pay today in taxes. Those making over $1 million a year would see the greatest benefit, a 0.7 percent decrease.

Whether or not Republicans plan to “fix” that significant injustice in the next 10 years is irrelevant. Americans must demand a tax plan that works on day one — and sadly neither the House nor Senate plan meets that minimum standard at this point.

More fair and reasonable fixes abound.

Instead of cutting the corporate tax rate from 35 percent to 20 percent, start somewhere more reasonable, like at 25 percent. That rate would make America more competitive internationally, while not decimating federal revenue overnight.

Republicans should maintain the alternative minimum tax to ensure that wealthy individuals who benefit inordinately from low tax rates on capital gains and dividends pay a minimum average tax rate on all their income; or Republicans could increase the tax rate on capital gains.

Maintaining the inheritance tax on estates worth more than $5.5 million, as it is today, would maintain several billion dollars in tax revenue each year.

Finally, the GOP is wrong to target for elimination the Affordable Care Act’s tax on those who forgo insurance. The individual mandate tax is only applied to those who cannot show that a “hardship” is preventing them from purchasing insurance.

The tax is an important provision of the ACA and one we have long supported as a way to push younger, healthier individuals to participate in health insurance pools and not game the system by only purchasing insurance after an accident or devastating diagnosis.

We suspect President Donald Trump, with his massive fortune awaiting his children, his own multimillion-dollar benefit from eliminating the alternative minimum tax and his personal vendetta against Obamacare, is to blame for these bad policy decisions Republicans are making.

We’d much prefer a modest tax cut or net-neutral plan that broadens the base by eliminating tax avoidance while lowering the tax rate. The current shenanigans Republicans are pulling in pursuit of a $1.4 trillion tax cut are unacceptable.

We still support the general direction Republicans are headed, but we expect better of our members of congress than what amounts to an elaborate accounting lie told to lower-income Americans too busy working multiple jobs to send a lobbyist to Capitol Hill.