House Republicans’ latest attack on the Affordable Care Act isn’t expected to go far, but it will show disagreements within the Democratic Caucus as the Supreme Court begins hearing oral arguments on the Obama administration’s landmark law later this month.

Democrats charge that the division on President Barack Obama’s hallmark legislative accomplishment is old news and dates back to the rigorous debate during the measure’s drafting in 2010. Republicans insist their latest proposal, to scrap a 15-member panel tasked with finding Medicare savings, helps build their case that the entire law should be overturned.

“I was really surprised, frankly, this morning with the amount of support we had for [the] repeal from the other side of the aisle for folks who actually voted for the bill in the first place,” Republican Policy Committee Chairman Tom Price (Ga.) said, noting the Energy and Commerce Committee’s voice-vote approval Tuesday to repeal the Independent Payment Advisory Board.

The bill, sponsored by Rep. Phil Roe (R-Tenn.), has 20 Democratic co-sponsors and will be marked up Thursday in the Ways and Means Committee. It would overturn a provision that Republicans charge could lead to higher Medicare rates and rationing and that some Democrats, including Reps. Frank Pallone (N.J.) and Allyson Schwartz (Pa.), say undermines Congressional authority.

Democratic sources said Tuesday that White House aides were reaching out to Members to keep them from peeling off when the measure comes to a vote on the floor. Democratic House leaders rigorously whipped colleagues against voting for the GOP’s full health care repeal last year, but they have not done the same for the more targeted repeal measures that have come forward.

Schwartz, a co-sponsor of Roe’s bill, sent a letter to colleagues last year calling on them to support the repeal of IPAB, calling it a “flawed policy” that won’t contain costs.

“Abdicating this responsibility, whether to insurance companies or an unelected commission, would undermine our ability to represent the needs of the seniors and disabled in our communities,” Schwartz said in the letter sent last April.

Schwartz carries a leadership role at the Democratic Congressional Campaign Committee and is a frequent defender of party ideals on the cable news circuit. Pallone serves as the top Democrat on the Energy and Commerce Subcommittee on Health. Neither Member, however, said their support of an IPAB repeal is harmful to the party.

“It’s my confidence in the provisions in improving care and reducing costs that enables [me] to feel so comfortable in repealing the IPAB,” Schwartz said in an interview.

Last week, Pallone blasted the GOP’s repeal efforts as “an effort by the other side to continue its political game of defacing the Affordable Care Act.”

Republicans have taken a piecemeal approach since last year to pick away at the law. Their previous effort came last month, when the House voted to undo the Community Living Assistance Services and Supports Act, a long-term care section of the law that the administration itself had deemed unworkable. Twenty-eight Democrats joined 239 Republicans to support a repeal of that provision.

The health care law turns 2 years old March 23, and the Supreme Court’s proceedings are expected to occur shortly after that milestone. While the arguments were likely to coincide with budget debates in the House, the Budget Committee might not pass its budget resolution before oral arguments conclude. The IPAB repeal, with companion legislation sponsored by Sen. John Cornyn (R-Texas), could provide the best messaging tool for the GOP during that last week in March.

“I think the American people understand this bill is terribly flawed and needs to go away. And although we would have liked to have greater recognition for the repeal bill we already took, it’s clear the American people want us to continue with our push,” Price said.

Democrats contend the timing is purely political. And while they acknowledge that the health care debate has caused Democrats heartburn and intraparty squabbling in the past Congress, it remains a hallmark of the party’s platform, and leaders intend to defend it.

“Obviously, there’s differences of opinion, as you know,” House Minority Whip Steny Hoyer said Tuesday during his weekly briefing with reporters. “This was a Senate provision, you understand. It was not in the House bill, and of course, we did not conference on the bill.”

The Maryland Democrat taunted Republicans for failing to overturn the health care reform law outright, noting that just three members of his Caucus voted for outright repeal last year.

“I think there’s overwhelming sentiment to fix some parts of it,” Hoyer acknowledged. “But I think there’s very, very strong support in the Democratic Party, and I believe that citizens are coming to that more and more as they see the benefits of that accruing to seniors in terms of their prescription-drug bill being reduced.”