They’re celebrating in Washington, after the Senate’s passage of a massive tax overhaul, thanks, in part, to a vote cast by Maine’s Sen. Susan Collins yesterday evening. The bill, which had passed the House shortly before, is a win for President Trump, whose legislative victories this year have been few and far between.

“Does this tax cut make the American people better off ?” Collins, who signaled her support for the bill on Monday, was quoted in an AP report. “The answer to that question is yes. The bill puts money back into the pockets of the American taxpayer with tax cuts beginning Jan. 1.”

There are some things to cheer about — the doubling of the child tax credit and the doubling of the standard deductions used by most households. Those cuts, however, expire in 10 years.

Corporations will have it better — their rate will be permanently slashed from 35 to 21 percent.

By the year 2023, those earning less than $30,000 will actually see a tax increase, according to the Joint Committee on Taxation. And “… by 2027, it would boost average levies for everyone earning up to $75,000,” the AP reported.

Keep in mind that Maine’s median income was only around $53,000 in 2016.

Meanwhile, the nonpartisan Tax Policy Center reaffirmed the big winners under the tax plan are the top 1 percent earners — those making more than $733,000 would see an average tax cut of $51,140.

And let’s not forget the additional $1.46 trillion the overhaul adds to the national debt.

Collins said her support hinged on the caveat that Congress passes two bills to stabilize the health insurance market. Yet, as any grade-schooler can tell you, Congress consists of two chambers, and we’ve heard of no guarantees that the House will pass the bills Collins wants.

Also worrying, the tax bill contains a provision that would eliminate the Affordable Care Act’s mandate that all American’s have health insurance or face a penalty. That penalty is in place in order to lower health care costs for all, but once repealed, 13 million people will likely lose their insurance, according to the Congressional Budget Office.

Collins was one of a handful of Republicans this year to stand fast against shortsighted attempts to repeal and replace the ACA.

But supporting the tax plan, she wound up helping undercut her own efforts to support healthcare in America in the name of a $53,000 handout for those who need it the least.

Susan Collins, what were you thinking?