Now, comes the sell.

Hours after Congress sent a sweeping package of tax cuts to the White House for President Donald Trump’s signature, the powerful network of advocacy groups backed by billionaires Charles and David Koch went into high gear to turn around the bill’s dour poll numbers. Planned to last at least six months—heading right into the months when voters will turn their attention to the 2018 midterm elections—the multi-platform Koch-backed campaign will seek to explain the benefits of the tax package.

“Given that the tax reform bill was just finalized, there’s a lot of work to be done educating Americans about its benefits,” said James Davis, an executive vice president at Freedom Partners, the hub that coordinates Koch-backed political activities. “We will make a massive push to show how pro-growth policies can revitalize the economy and open the floodgates to new opportunity, innovation and prosperity.”

The sales job will be tough. Polls find the proposal incredibly unpopular with voters: a CNN poll released this week found 55% of voters opposed to the bill. And for good reason. The bulk of the benefits will go to those who make more than $300,000 a year, according to the non-partisan Tax Policy Center. And, by 2027, those earning less than $75,000 annual will see a tax hike while the cuts for the ultra-rich remain, according to the Center for Budget and Policy Priorities.

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Democrats, who stood unified against the package, now plan to weaponize it against Republicans next year and beyond.

Republicans grumble that they had little choice but to pass this unpopular bill. For years, they’ve promised sweeping tax cuts. Now, given control of the House, the Senate and the White House, they delivered on campaign rhetoric in a big way. Failing to do so would have meant they had control of all levers of official Washington power and still accomplished nothing. They had to show they could, in fact, govern.

At the same time, it’s fast approaching the end of Trump’s first year in office. Aside from the confirmation of judges, including a Supreme Court justice, and regulatory moves, the GOP has not passed a significant piece of legislation. The pressure is on to do so before next year’s elections, when the entire House and a third of the Senate are up for grabs.

A multi-million dollar campaign

The Koch-backed network spans interest groups, advocacy organizations, think tanks and P.R. machines. It went in with $20 million to push for these tax cuts and promised lawmakers that their backs would be covered if they supported it.

An internal report said the Koch organizations knocked on more than 33,000 doors to tell voters about the tax bill’s potential, reached more than 16 million people via digital ads online and ran 111 different digital campaigns. The cost for Wisconsin alone, where many worried about a defection from Republican Sen. Ron Johnson and the re-election bid next year of Democratic Sen. Tammy Baldwin, was $1.6 million.

To build on that, the Koch network on Friday plans to let members of Congress know that the team will be organizing town halls, seminars and workshops in their districts and states to try to re-frame the talk on the tax bill. At the same time, the advocacy groups, such as Americans for Prosperity, will incorporate the pro-tax cuts message into their phone calls and door knocks.

Finally, there will be television, radio and digital ads to promote the bill and, in some cases, the lawmakers who cast votes that made it possible.

All told, they’re eyeballing several million dollars to defend the bill and to try to take some of the sting off the vote backing it.

Koch-world officials say a tremendous about of “misinformation” about the bill made it unpopular, but perhaps not permanently. They plan to cast the bill’s critics as tax-loving liberals who are sour that they lost a political fight.

“This tax plan is big, bold, and pro-growth. It’s about to ignite a new era of growth, and we’re going to make sure that Americans understand how they and their community stand to benefit,” said Americans for Prosperity President Tim Phillips. “That means activating our grassroots infrastructure in 36 states to get the word out, having hundreds of thousands of direct conversations that cut through the rhetoric and misinformation.”

Still, the tax bill is just as unpopular on the day it is becoming law as the Democrats’ health care bill was when it became law in 2010. Republicans used Obamacare as to bludgeon their way into the majority that year. Even so, views of Obamacare have improved in the years since. Republicans are hoping their tax cuts will fare as well.

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Write to Philip Elliott at philip.elliott@time.com.