After searching for months to find an attorney who would take their case, House Republicans made good on their threat to sue the Obama administration Friday, filing a lawsuit challenging the president's authority to enact key parts of the Affordable Care Act.
The case has been considered a long shot by legal scholars, as the Supreme Court has repeatedly rebuffed members of Congress suing on constitutional grounds.
But if successful, the lawsuit could jeopardize billions of dollars in aid to help low-income Americans get medical care.
It marks yet another attempt by critics to use the courts to pull apart the health law. A separate legal challenge that takes aim at other financial assistance for low- and middle-income insurance consumers is scheduled to be considered by the Supreme Court next year.
Filed a day after the president announced executive actions to halt deportation of millions of immigrants living in the country illegally, the new suit also underscores rising tensions between Obama and congressional Republicans.
"Time after time, the president has chosen to ignore the will of the American people and rewrite federal law on his own without a vote of Congress," House Speaker John A. Boehner (R-Ohio) said Friday.
Boehner is under pressure from the restless conservative wing of his party to take a more confrontational approach toward the president in the wake of the GOP's victories in midterm elections this month.
The lawsuit, which targets the Health and Human Services and Treasury secretaries, focuses first on a controversial provision of the health law that requires large employers to provide health coverage to their employees or pay a penalty.
The so-called employer mandate is designed to prevent businesses from dropping health benefits now that the government provides subsidies to help low- and moderate-income Americans buy coverage. The architects of the law worried companies would be tempted to stop offering coverage, shifting the cost to taxpayers.
The mandate, which requires extensive reporting by businesses, is unpopular with employers and with congressional Republicans.
The Obama administration has wrestled for years with implementing it, twice delaying enacting the mandate.
Each time, administration officials said they were acting under authority that gives federal officials the power to phase in changes to tax law.
House Republicans charge the administration exceeded its authority.
The lawmakers also argue the administration did not have authority to fund a program that is supposed to help low-income Americans with co-pays and deductibles if they purchase health plans through the health law.
The nonpartisan Congressional Budget Office estimates that the program will cost about $3 billion this year, paid to insurance companies to reimburse them for providing discounts to their low-income customers.
Those payments have been made all year. But Congress never specifically appropriated money for the program.
That violates the Constitution, according to the lawsuit. Congress "has a necessary role — indeed the defining role — in our system over any expenditure of public funds," the suit says.
The White House issued only a one-sentence response to the case. "Instead of passing legislation to help expand the middle class and grow the economy, Speaker Boehner and House Republicans are spending hundreds of thousands of taxpayer dollars pursuing a lawsuit that is without any sound legal basis," said spokeswoman Brandi Hoffine.
Democrats for months have charged that Republican plans to sue were purely political.
House Republicans struggled to find attorneys to take the case. Several prominent law firms turned them down.
This week, Jonathan Turley, a professor at George Washington University Law School, announced that he would take the case, citing his longtime concerns about the rise of executive power.