Democrats spent the week warning that the Republican tax reform bill will be seen by voters as a giant tax cut for corporations, and will doom the GOP in the 2018 elections.

But Republicans weren't having any of that.

Instead, House and Senate leaders were on schedule to pass the bill early next week, and many said they believe the legislation would improve their chances of winning races in 2018.

"I think it will help us. I think this tax bill will be a big achievement for us, and overall it will be good," said Sen. Richard Shelby, R-Ala. "Overall, it's not perfect ... But I like a lot of things in it."

"I believe that this creates more jobs, better jobs, higher-paying jobs, and if that turns out to be true, it's helpful in 2018," said Sen. Jerry Moran, R-Kan., who added that some of the effects will be felt by the American public ahead of the election. "They'll be felt to some degree, but this is a matter of improvements to the economy over a long period of time as well."

Republicans were thrown off their guard last week when they lost what should have been an easy Senate victory in Alabama. That led some Democrats to say things are tilting their way, and that the tax bill could compound the GOP's problems a year from now.

But House Speaker Paul Ryan, R-Wis., cast the tax bill as an example of delivering on Republican promises to voters.

"No, because if we do our job, if we keep our word, if we make good on our promises, we're going to be just fine," Ryan said last week if he was worried about a Democratic wave. "That's what we're in the middle of doing."

The tax bill has polled poorly with voters. But even there, Ryan said tax reform from 30 years earlier also wasn't accepted right away by the public. He noted that only 18 percent of people believed they would benefit from the 1986 tax legislation signed into law by President Ronald Reagan.

"This is the nature of the debate on things this big, like tax reform," Ryan said. "You've got pundits and spinsters and all of this — spinmeisters out there confusing the public, and so that's what I think is happening here with tax reform like you see with any large piece of legislation."

"The results are going to be what sells this bill, not the confusion before it passes," Ryan said.

Still, Republicans are facing headwinds as they get ready for the midterms. According to a new Monmouth poll, Democrats hold a 15 point advantage (51-36 percent) over Republicans on the generic congressional ballot. Additionally, 64 percent of those asked oppose the tax bill, according to a new Harvard CAPS/Harris Poll.

Republicans finished rewriting the legislation on Friday, which will cut the corporate tax rate, introduce temporary tax cuts for many households, and include an expanded refundable child tax credit at the behest of Sen. Marco Rubio, R-Fla., who threatened to vote against the bill without the increase.

Assuming it passes and is signed into law next week, Democrats will have a year to test their theory that the public will start turning against Republicans.

They were already starting last week. House Minority Leader Nancy Pelosi, D-Calif., declared that Republicans in suburban districts will be in "very serious trouble."

"It's going to be a real hard sell for Republicans that what they delivered was a gigantic tax cut for big corporations paid for in one way or another by everybody else in the country," said Sen. Chris Van Hollen, D-Md., the chairman of the Democratic Senatorial Campaign Committee.

"That is not what people bargained for," Van Hollen said. "So it's going to be a big wake-up call."