It’s about time Sen. Susan Collins gets an apology from all of those people who have been calling her a “RINO.”

That’s short for “Republican In Name Only,” and it’s meant as an insult from people who think she is not fully committed to her party’s values.

But Collins’ vote in favor of the Senate tax bill last week proves that the critics have been wrong. If being a “real Republican” means supporting policies that promote income inequality and leave the middle class to fend for itself, Maine’s senior senator has nothing to be ashamed of.

Collins might stray from her party when it comes to an issue like health care, because health care is not really a Republican concern – their eight years of moaning about Obamacare notwithstanding. When they found themselves in control of both the legislative and executive branches of government, it turned out that there was no Republican health care plan that could attract a majority of Republicans, let alone anyone else.

But taxes are different. Lower taxes and smaller government are what “real Republicans” are all about, and tax cuts are their policy cure-all for everything that ails America.

The final details of the plan are being worked out, but Collins and almost all of her colleagues have approved borrowing about $1.5 trillion – give or take a hundred billion here or there – to hand out to corporations, privately held businesses, wealthy families and individuals. It’s not the biggest tax cut ever, but it’s probably one of the most lopsided, according to an analysis in The Washington Post’s Wonkblog, because so many of the benefits are targeted toward people who already have so much.

Republicans say their bill will help the middle class, too, but it can’t help much. The reason isn’t complicated. Since the rich pay the most taxes, tax cuts help the rich most.

The next step is the small government part. About half of the federal budget goes to Social Security, Medicare and Medicaid now, and as more baby boomers move into retirement, there will be pressure to cut benefits. Unlike the tax cuts, “entitlement reform” will barely affect people at the top of the wage scale, but everyone else will feel the pinch.

Collins has secured commitments from Republican leadership to waive an automatic $25 billion cut in next year’s Medicare budget that would have been triggered by growth in the deficit, but even if they keep their promises – the ability for the federal government to meet the need of an aging population is going to fade as the cumulative impact of the tax cuts takes hold.

This is not the Trump agenda. It’s the Republican agenda, and these are the same bills that would have passed if any of the other 16 Republican contenders for the presidency had won the last election.

None of this should be a surprise. Of all the shocking things that have occurred in the last year, Republicans voting to cut taxes on the rich could compete with the Patriots winning another Superbowl and the roll-out of another iPhone for the title of least surprising event of 2017. Cutting taxes is what Republicans do. The question now is, what are Democrats going to do about it?

They have had a pretty good year politically without having to exert any effort. Between the Russia investigation, the sudden popularity of the Affordable Care Act and the you-can’t-look-away-for-a-second presidency of Donald Trump, the opposition party is hoping to make serious gains in the 2018 midterm elections, maybe even taking back the House of Representatives.

But to do that, they would have to be able to say what it is they all believe – the way every Republican from Susan Collins to Ted Cruz believes in tax cuts.

And unless it’s “Donald Trump is not a normal president,” we haven’t heard it yet.

Democrats are all blasting the tax bill, but are any of them running for Congress next year calling for a tax hike for corporations or the people who report more than $1 million a year in income?

And, if so, how would they propose spending the money? Would they offer more than restoring funding to programs that are already not doing enough to help the middle class?

It’s understandable that people are angry at Collins for her vote, but being mad at Republicans for sticking to Republican principles seems a little pointless.

We have a two-party system, and one of the parties has made it clear what it believes in. If the other party has anything to say, it should speak up.

Greg Kesich is the editorial page editor. He can be contacted at:

gkesich@pressherald.com