“If you get to the second ten years, it’s the single most important form of financing,” said Douglas Holtz-Eakin, who served as the director of the Congressional Budget Office from 2003 until 2005.

House and Senate Democratic leaders are quietly looking for way to repeal the tax, perhaps as early as this year. An alliance of insurance, business and union groups is pushing for Congress to eliminate it, and lawmakers have introduced bills to get rid of the tax in both the House and the Senate.

The non-deductible tax would cost 40 percent of the value of an employer-provided healthcare plan above a certain cost threshold. For family coverage, the tax would kick in for plans costing more than $27,500 in 2018. Individual coverage sponsored by employers would be hit for plan values that exceed $10,200.

The provision was included in the law not only as a way to pay for Obamacare, but to curb the cost of healthcare by discouraging so-called luxury healthcare insurance.

But Democrats are no longer supporting the tax and say the “Cadillac tax” is a misnomer because of the rising cost of healthcare.

“The ‘Cadillac tax’ will raise barriers that would deprive patients of needed cancer screenings, diagnostic tests and lifesaving treatment,” said Rep. Joe Courtney, D-Conn., who is the sponsor of a House bill to repeal the tax. “We must repeal this onerous tax before it diminishes the progress we have made since enactment of the ACA.”

The legislation is gaining support in both the House and Senate. A second House bill, sponsored by Rep. Frank Guinta, R-N.H., has 100 GOP co-sponsors.

The issue is migrating from the halls of Congress to the presidential campaign trail.

Sen. Bernie Sanders, I-Vt., is a longtime opponent of the Cadillac tax and has sponsored a Senate bill to repeal it. His Democratic opponent, Hillary Clinton, now says she also supports getting rid of the tax, and Sanders’ bill is cosponsored by Sen. Chuck Schumer, D-N.Y., the No. 3 Senate Democrat who is poised to become Democratic leader in 2016.

“The reality is that the plans this bill will tax are more like Chevrolets,” Sanders said.

But the effort to get rid of the tax face two formidable opponents: Republicans and President Obama. Obama says he opposes any bill that puts the Affordable Care Act on shaky ground, and removing a big funding source would do just that.

And while Republicans want the tax gone, they want to kill it in their own legislative effort to cut out most of the major pieces of Obamacare. The House passed legislation last month that would repeal most of the law, including the Cadillac tax, and allow the Senate to follow with just a simple majority.

Democrats don’t support the bill, but may try to negotiate a deal with Republicans to pass legislation that would eliminate both the Cadillac tax and the unpopular 2.3 percent medical device tax, which is expected to raise $26 billion over the next decade.

Holtz-Eakin said Republicans will probably steer clear of helping Democrats out of a political dilemma of their own making.

“I don’t see why the Republicans will jump to their assistance, and I don’t expect them to, frankly,” Holtz-Eakin said. “This is the Democrats’ problem. They created it.”

But others are more optimistic.

James Klein, who is president of the American Benefits Council, a trade association made up of major Fortune 500 companies, said both parties dislike the tax and will be motivated to find a way to repeal it.

“What is really unique about this issue is, not withstanding widely disparate view on the Affordable Care Act, the need to repeal this tax is something that Republicans and Democrats broadly agree on,” Klein told the Examiner.