A lot has been made about the deal that Maine Sen. Susan Collins cut in exchange for her vote for the Republican tax reform plan that became law Friday.

Some argued that Collins had been “duped” because the two health care bills that she had been told would be passed by the end of the year won’t even be considered until next spring.

Collins countered that she deserves credit for hard bargaining, winning back tax deductions that had been slated for elimination in earlier versions of the package.

But the argument misses the point. Whether Collins was a winner or loser at the bargaining table is less important than the fact that she voted for the bill at all. That even a self-proclaimed “fanatical moderate” would line up with the most extreme members of her party to pass a major piece of legislation should serve as a reminder of how much ideology matters at a time when partisanship is supposed to be out of style.

As we have said before, the substance of the Republican tax package is a rehash of trickle-down economic theories that have proven not to work – at least not for working-class and middle-class Americans who want to get ahead. In the short term, it will benefit the already-wealthy most. In the long term, it drops a time bomb in the federal budget that will put pressure on Social Security, Medicare and Medicaid, negatively affecting people who are already struggling.

UNPOPULAR BILL

If you can believe the polls, the bill is unpopular, getting only 33 percent support. But it is nearly universally backed by Republican office holders, with 94 percent of Republican House members voting yes along with every Republican senator who was well enough to be present. Not a single Democrat in either body sided with them.

Collins does not fit the mold of a partisan warrior. She is rightfully proud of being named “the least partisan senator” by the Lugar Center four years running, and she’s become the co-chair of No Labels, a nonpartisan organization that is dedicated to finding common ground between Democrats and Republicans. When she announced this year that she would stay in Washington and not run for governor, she said she hoped to serve as “a bridge” in Washington, and her votes against the “repeal and replace” of the Affordable Care Act last summer were heroic in the face of intense pressure by Republican donors and her political base.

When the Senate version of the tax bill emerged, Collins made clear that she would not be an automatic yes, expressing her opinion that people reporting more than $1 million a year in income should not get a tax rate cut. She later said that it was a mistake to include the elimination of the Affordable Care Act’s individual mandate – projected to result in a decade of 10 percent annual premium increases – in the tax bill. But both of those features were in the bill she ended up supporting.

Collins did bargain to make the bill marginally better than it might have been, but she never challenged its underlying logic – which was that a 40 percent tax rate cut for corporations that are enjoying near-record profits is more important than helping middle-class families, who struggle to pay for health insurance, higher education and secure retirements. Another foundational supposition: That it would be worth borrowing $1.5 trillion to stimulate growth in the gross national product, even if the rewards of that growth would be distributed in a way that makes already-historic economic inequality even worse. The wealthiest 1 percent of Americans have absorbed 85 percent of the country’s income growth since the Great Recession, and this tax bill does nothing to stop that from happening again.

REPUBLICAN IDEOLOGY

This was an ideologically Republican bill, very different from the kind of populist economic policy that candidate Trump advocated in 2016, and passed in a very different way than the collaborative process usually espoused by moderates like Collins.

The tax bill has to be viewed as part of a broader Republican agenda, which includes packing the federal courts with young, right-wing judges and dismantling regulations, including those that protect the environment and access to the internet.

This was the prize the Republicans won in 2016, when they were given control of the legislative and executive branches of government, and they have used it to push through an unpopular ideological agenda that was cooked up in the party’s right-wing think tanks.

And this is the paradox: If you ask Americans if they are liberal or conservative, you’ll only find a few ideologues. According to the American National Election Studies, which have interviewed voters since 1948, most people put themselves somewhere in the middle of the spectrum, with more people identifying as “moderate” than as “liberal” and “conservative” combined. But there is no political ideology called “moderate,” and parties are ideological organizations.

Democrats stand to benefit next year from a partisan backlash against the Trump-Republican agenda, just as Republicans benefited from backlash against partisan policies Democrats passed the last time they had all the reins of power. Toggling back and forth between Democratic and Republican control is one way to prevent excess, but it’s no substitute for finding common ground.