A budget plan offered by House Budget Committee Chairman Paul Ryan (R-Wis.) would cut federal spending by $5 trillion over the next decade by effectively repealing the Affordable Care Act, making deep cuts to Medicare and dramatically cutting taxes for the nation’s wealthiest earners. (J. Scott Applewhite/AP)

Congressional Democrats said Wednesday that the new House Republican budget plan will play a central role in Democratic midterm election strategy.

The head of the House Democrats’ campaign arm said that the budget plan by House Budget Committee Chairman Paul Ryan (R-Wis.) will be the “defining issue in the midterm elections.” And Senate Majority Leader Harry M. Reid (D-Nev.) suggested that Ryan’s budget was “nothing more than a blueprint” for implementing policies sought by Charles and David Koch, the wealthy industrialist brothers who are spending millions of dollars on television ads designed to defeat congressional Democrats.

The Ryan plan released this week closely resembles the House GOP budget requests proposed and passed in recent years. The plan would cut federal spending by $5 trillion over the next decade by effectively repealing the Affordable Care Act, making deep cuts to Medicare and cutting taxes significantly for the nation’s wealthiest earners.

The House Budget Committee passed the plan Wednesday evening along party lines after a day-long hearing, and the full House is expected to vote on it next week. It stands no chance of winning passage in the Democratic-controlled Senate, though it has become a topic of discussion there anyway.

“Thank you, Congressman Paul Ryan, for reminding us what Republicans would do if they had control,” Sen. Richard J. Durbin (D-Ill.) told reporters. “That they would cut student loans, that they would cut food stamps, that they would cut basic programs for middle-income families.”

Durbin defended Democrats’ decision to focus again on a Ryan budget plan, suggesting that voters’ concerns with the health-care law will be replaced in the coming months with a focus on the nation’s still struggling economy, especially now that more than 7 million Americans have signed up for health plans under the new law.

But running against Ryan’s proposals has resulted in mixed success for Democrats in recent years. While President Obama and Senate Democrats successfully ran against his spending plans in 2012, Democrats gained only a few seats in the House and Republicans maintained the majority. In 2010, Democratic attempts to warn against GOP spending proposals were trumped by widespread opposition to the new health-care law, resulting in the election of dozens of new House Republicans.

Rep. Steve Israel (D-N.Y.), who leads the Democratic Congressional Campaign Committee, said Ryan’s budget will be critical to drawing contrasts in close races this fall. During an appearance at the National Press Club, he announced the launch of a new DCCC initiative, called “Battleground Middle Class,” that will use robo-calls, online advertisements and field work by Democratic operatives to “hold Republicans accountable in their district,” he said.

But House Democrats face a steep climb in their quest to win the majority. They need to pick up 17 seats, a goal that even Democratic strategists privately acknowledge is highly unlikely against the backdrop of Obama’s lingering unpopularity.

“It’s a tough climate for us right now,” Israel said, adding, “But I believe this Republican budget helps change the narrative by reminding voters who has their backs.”

Andrea Bozek, a spokeswoman for the National Republican Congressional Committee, countered that the health-care law and Obama’s image will be the focal points for the rest of the campaign.

“In 2012 — with President Obama on the ballot — Steve Israel called Paul Ryan the Democrats’ ‘majority maker,’ yet his party didn’t even come close,” she said in a statement. “We hope Democrats keep running on their support of Obamacare’s drastic cuts to Medicare, opposition to a balanced budget, and support for an unpopular President.”

A vote on the budget is expected in the full House in the coming days, according to senior leadership aides. As he sought to build support for the plan, House Majority Whip Kevin McCarthy (R-Calif.) told colleagues in a closed-door meeting Wednesday morning that the budget “is the same budget almost all of you voted for last year,” according to aides familiar with his remarks.

“I expect you will vote for it this year — after all, you’re not all running for the Senate in Georgia,” McCarthy joked, according to aides.

The joke was in reference to the three House Republicans from Georgia — Reps. Paul C. Broun, Phil Gingrey and Jack Kingston — who are running against each other in a primary for the state’s open Senate seat. All three have bucked party leadership in recent months in efforts to appeal to the state’s conservative Republicans. They are expected to be among a handful of fiscally conservative Republicans who will vote against the Ryan budget out of concern that the proposal would not sufficiently cut federal spending.

Sean Sullivan and Wesley Lowery contributed to this report.