Congressional Republicans’ collective sigh of relief after passing tax legislation may seem confusing. Won’t voters hold them accountable in 2018 for passing such an historically unpopular bill? The answer is “no,” for several reasons.

First, the bill’s unpopularity may be somewhat overstated. A lot of the disapproval expressed in surveys is more about the bill’s sponsors than about the bill itself. In these polarized times, almost anything carrying the president’s endorsement is going to be a nonstarter for more than half the population. If Trump were to designate ice cream the official White House dessert tonight, at least a third of us would stop “screaming for it” tomorrow.

This is not to say that this legislation should be more popular. But let’s face it, efforts to win over Blue America with fewer corporate tax cuts, fewer cuts for wealthy individuals or fewer changes to popular tax breaks would have probably fallen on deaf ears in this environment.

Placating the base

More importantly, as University of Glasgow political scientist Christopher Jan Carman and I have found, Republicans in Congress simply don’t care as much about public opinion as Democrats do. The ideological convergence between voters and legislators is more than three times greater among Democratic legislators than among Republicans.

And there is good reason for this: Republican voters don’t really care either. Across several years of data, we found that Republican voters are between 20 and 30 points less likely than their Democratic counterparts to agree that elected representatives should “try their hardest to give the people what they want.”

Why? Many Republicans – voters and lawmakers alike – simply cherish their principles more than they do the preferences of a largely capricious and inattentive public. And nothing is more central to Republican orthodoxy than tax cuts for the wealthy. If they can’t cut taxes when they have control of the presidency and both houses of Congress, what do they have to live for? To be sure, if Republican lawmakers hadn’t gotten this done now, while they had the chance, they could have expected donors to ignore their calls next year.

But this goes well beyond fundraising. The first elections members of Congress need to worry about next year are the primaries. If they were to have nothing to show for their two years in power – which, until now, they arguably didn’t – they could have expected to face serious primary challenges. Make no mistake, everyone in the GOP remembers what happened to former House Majority Leader Eric Cantor in 2014, not to mention Dick Lugar, Mike Castle and Bob Bennett before him.

Republicans also know that their collective fate in 2018 depends on voter turnout. Unlike presidential years, when heavy mobilization efforts, media focus and social pressure leads most voters who are even remotely interested in politics to go to the polls, midterms are much lower-profile affairs. Almost always, the party that controls the presidency loses seats, because dissatisfied voters are more motivated to seek revenge at the ballot box. And that tendency may be heightened in 2018, if recent rallies or elections are any indication. But by slashing taxes and destroying Obamacare in one fell swoop, Republicans might motivate their base enough to at least contain their losses.

But isn’t there plenty in the new law to motivate Democrats as well? Certainly: If reduced deductions on mortgage interest, charitable deductions, state/local taxes, graduate students’ tuition waivers, teacher supplies and so on don’t get the Democrats’ backs up, the repeal of Obamacare’s individual mandate surely will. But here’s the deal: There are plenty of other things motivating the Resistance right now, so the Left was going to turn out in 2018 regardless. If the GOP hadn’t done something to counter that tide, they may have faced an electoral tsunami.

Claiming credit

But this is not just about playing defense.

Long-term policy consequences aside, the GOP had a lot to gain, politically, by passing this bill. The economy has been gaining steam over the past year, and while this tax bill probably won’t produce the growth that its proponents claim it will, it probably won’t reverse the trend either, at least not in the short term.

If GDP growth is still humming along in two years, Republicans will credit this legislation. And if history is any guide, Trump will be well-positioned for reelection – despite all the reasons why Democrats may find that prospect mind-blowing.

Yes, growth will have preceded the cuts. Yes, the causal relationship between cuts and growth is tenuous anyway. And yes, the cuts will swell the deficit and expand inequality. But as we all surely know by now, such facts don’t really matter all that much anymore, and maybe they never did. After all, Republicans have never wavered from their insistence that the Reagan tax cuts of 1981 ushered in strong growth later that decade. Such faith contributed to big GOP victories in 1984 and 1988, and continues to inform Reagan nostalgia on the Right.

And if Trump wins reelection, everything else that we associate with his candidacy and his presidency may be validated and copied by future politicians, on both sides, as “the way to win” – leaving a political legacy that may far outlast the consequences of this tax bill.