In advance of expected congressional action to overhaul the tax code, both political parties are seizing on the effort as key to their 2018 midterm election prospects.

House and Senate Republicans believe passing the first tax code rewrite since 1986 will fulfill a key promise they made to voters in 2016 — and will spur economic growth and job creation that voters will credit them for in the 2018 midterms.

Congressional Democrats, meanwhile, believe the GOP’s tax bills (the House and Senate currently have separate plans) are so bad that they’re giving Democrats another powerful messaging tool for the midterms.

“This tax bill will be at the center of our efforts to take back the House and the Senate in 2018,” Senate Minority Leader Charles E. Schumer of New York said alongside House Minority Leader Nancy Pelosi of California at a press conference Monday at the Democratic National Committee.

“Taxes combined with health care will be a powerful one-two punch for Democrats on the campaign trail,” he said.

Speaker Paul D. Ryan, however, thinks everything will be OK for his party when it comes to the politics of taxes.

“When we do this, we’re going to be just fine politically,” the Wisconsin Republican said at his weekly press conference last Thursday. 

Despite Ryan’s confidence, Republicans are clearly worried about some of their own members who have come out in opposition to the plan and others who might do so in the coming days.

On Monday, 45Committee, a pro-Trump political group, launched television ads in nine Republican-held districts in New York, New Jersey and California urging members there to vote for the tax bill. The ads are targeting New York Reps. Lee Zeldin, Dan Donovan, John J. Faso and Claudia Tenney; New Jersey Reps. Leonard Lance and Christopher H. Smith; and California Reps. Darrell Issa, Steve Knight and Jeff Denham.

Democrats are also targeting vulnerable Republicans. They held protests against the tax bill Monday in at least 25 House districts.

“Similar to the pivotal role they played in stopping the Republican healthcare repeal effort, we are witnessing a massive grassroots uprising against the Republican Tax Scam, and it’s growing stronger by the day,” Democratic Congressional Campaign Committee Chairman Ben Ray Luján said in a statement.

The DCCC day of action follows a weekend in which scores of Democratic incumbents and candidates held events to call attention to the tax bill, focusing on provisions Republicans have proposed repealing or curbing, such as the state and local tax deduction and the medical expense deduction, Pelosi said.

“It is an assault on middle-income families across the country,” the California Democrat said.

House Republicans leaders have scheduled their bill for a floor vote this week. Schumer said he’s been counting from afar, and they don’t have 218 commitments yet.

GOP leaders are asking their members to “walk the plank” for a bill that will never become law, Pelosi added.

She named some potentially vulnerable Republicans whose votes Democrats will be watching, including Illinois Rep. Peter Roskam, New Jersey Rep. Rodney Frelinghuysen, Texas Rep. Will Hurd and the entire California GOP delegation, counting House Majority Leader Kevin McCarthy. 

Pelosi said that while New York Republicans have realized the House tax bill could lead to tax increases for their constituents, she is surprised that more of their California colleagues haven’t come out against it.

“What is it they realize that hasn’t sunk in with Republicans across the country, especially in California?” she said.

Growing resistance

Pelosi predicted the resistance to the tax bill will only grow with President Donald Trump pushing for the 2010 health care law’s individual mandate to be repealed as part of the tax bill.

“When you get anywhere near health issues, you activate, you explode the activism,” she said.

Grass-roots mobilization against the bill is just getting started and “reaching a very high level,” Schumer said.

The New York Democrat cited a Joint Committee on Taxation estimate that said 19 million middle-class households would pay more in taxes under the Senate bill, calling the measure “political insanity, plain and simple.”

Democrats on the Senate Finance Committee charged that the GOP tax overhaul plan would lead to a tax increase on 13.8 million households earning under $200,000 in 2019, rising as high as 21.4 million by 2022, based on data released by the Joint Committee on Taxation.

Low- to middle-income households are still generally less likely to see tax increases than the ultra-rich, according to the JCT data, although tax filers with between $100,000 and $200,000 in annual income are more likely than millionaires to see a tax increase in the years examined.

“You can sort of smell when a wave is beginning,” Schumer said. “And that smell that was in the air in 2005 is in the air now,” he said, referring to the 2006 election that saw Democrats recapture the majorities in both chambers.