Senate Majority Leader Mitch McConnell (R-Ky.), left, speaks at the White House ON Wednesday following the passage of tax legislation. (Jabin Botsford/The Washington Post)

A couple with two children from Indiana, where Democratic Sen. Joe Donnelly faces a difficult reelection next year, explain to the audience that with combined wages of $73,000, they stand to save $2,000 under the Republican tax cuts enacted Wednesday.

A single mother with one child from North Dakota, where Democratic Sen. Heidi Heitkamp is in similar straits as Donnelly, describes how much more of her $41,000-a-year salary she can keep.

“She looks into the camera and she says, ‘Sen. Heitkamp, maybe $1,300 is not a lot of money to you. But for me, it’s a 73 percent reduction in my tax bill.’ ”

Senate Majority Leader Mitch McConnell (R-Ky.) was reading from a memo he had just pulled from his coat pocket listing ideas for TV ads that he expects Republicans to run in their campaigns next year.

Democrats have been claiming Republicans triggered a political tsunami by pushing an unpopular tax bill to President Trump’s desk for his signature.

McConnell defiantly disagrees. He has been thinking a lot about the 2018 midterms, and he wants everyone to know that he is confident that the tax vote will help.

“In no way do we believe this will be a political liability,” he said in an interview with The Washington Post.

“Trust me, we’re prepared to deal with this in a political context.”

As Congress ends a year marked mostly by gridlock and dysfunction, a sharp divide has emerged between the two parties.

Republicans believe they can save their House and Senate majorities by selling Trump’s first year in office as consequential and full of accomplishments. They tilted the Supreme Court back to the right, and they finished 2017 by enacting sweeping cuts for most taxpayers.

Democrats say the late burst of activity will not alter a broader perception of a Republican-controlled Congress that spent most of the year at a dysfunctional standstill. That die has been cast, they say, and the tax legislation can be portrayed as a giveaway to the rich at the expense of the middle class.

“Most members of the Senate, and members of the press corps, have been living on half rations for so long, that when any crumbs are put on the table, they jump out and announce that a feast has been delivered,” said Sen. Richard J. Durbin (Ill.), the No. 2 Democratic leader.

Will your taxes go up or down in 2018 under the new tax bill?

Recent history suggests it is difficult to change the public’s moribund view of Congress, but Republicans see a ray of hope as 2017 draws to a close.

A decade ago, as Democrats finished their first year controlling Congress with a flurry, 22 percent of voters approved of the institution’s performance, according to Gallup.

In December 2009, 25 percent of voters approved of the Democratic-controlled Congress, according to Gallup. It was an ignominious high-water mark: In the ensuing eight years, approval of congressional job performance cleared 25 percent just one other time, in February 2017.

This month, just 17 percent of Americans approved. Trump’s job approval has hovered between 35 and 40 percent, usually a warning sign for the president’s party heading into his first midterm. Next November, Democrats must gain 24 seats in the House and two in the Senate to claim the majority.

Last month, just 18 percent of Republicans approved of the job performance on Capitol Hill. But the number grew to 29 percent this month as the tax bill was poised for final approval. That's nowhere near good enough if Republicans expect to stay in power, but they see it as the beginning of a trend.

One area of opportunity: conservatives who had been furious at the lack of output despite total Republican control of Washington.

“What this week did was highlight the successes of a very successful year. And it made people look at the year in its entirety, and all of the sudden we have activists, voters, folks back home, talking about how different this year turned out,” said Sen. Cory Gardner (Colo.), chairman of the National Republican Senatorial Committee.

McConnell places the confirmation of Justice Neil M. Gorsuch at the top of the accomplishment list, reasserting a conservative majority on the Supreme Court. He then cites the tax plan and the dozen appeals judges the Senate has confirmed. Tucked inside the tax package is language to allow energy drilling in an Alaskan refuge and to terminate the Affordable Care Act’s tax penalty on those who refuse to buy health insurance.

“Look at the totality of the year and the significance of things that are done,” he said.

Democrats will talk about a tax bill that funnels most of its benefits through permanent corporate tax cuts, offering just a few years of breaks for middle-class taxpayers. They believe that centrist Americans in suburban strongholds will determine the victors next fall — and that the Republican end-of-year push will do little to change these voters’ minds about the GOP-controlled Congress.

“I think it’s baked in,” said Sen. Chris Van Hollen (D-Md.), the chairman of the Democratic Senatorial Campaign Committee. “And more than that, I don’t think the public is going to see a big tax cut to big corporations — that’s going to be paid for by millions of middle-class families with an increase — as an accomplishment.”

A day after final passage of the tax bill, Republicans could not muster up the votes for agreements on the budget, disaster relief, how to handle the more than 1 million undocumented immigrants who came here as children or legislation to stabilize insurance markets.

The most iconic image of 2017 on Capitol Hill remains the thumbs down that Sen. John McCain (R-Ariz.) flashed a few feet away from McConnell in a late-night vote that ended the GOP bid to fully repeal the Affordable Care Act.

“We have two things that happened this year, aside from the tax bill: the defense authorization and Gorsuch,” Durbin said, mocking Republican claims of productivity. “Come on, this is the United States Senate.”

McConnell has focused most of the Senate’s floor time on confirmation votes, both for Cabinet picks and judges. His top goal has been to help Trump transform a judiciary that Barack Obama tilted decidedly to the left in his eight years as president.

McConnell is proud of the lasting policy impact of the agenda — and believes it will be enough to persuade voters to keep Republicans in power.

“If you want to change the country, if you want to use your majority to do important things that last, think of three things bigger than the Supreme Court, circuit courts and taxes,” McConnell said. “How long [tax cuts] last obviously depends on the American people and who they elect.”

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