But these are the early rounds in preliminary bouts. The one that really counts - a showdown at the Supreme Court - is at least a year away.
The health care law suffered its first major legal setback Monday when a federal judge . The decision handed Republican foes ammunition for their repeal effort next year.
Judge: Health Care Mandate Unconstitutional
CBSNews.com Special Report: Health Care Reform
In his decision, U.S. District Judge Henry E Hudson said Congress overreached when it mandated all Americans must buy health insurance, reports CBS News correspondent Nancy Cordes. The Constitution, he said, does not allow that kind of "unchecked expansion of Congressional power."
"It's about an individual's right to choose to participate," he wrote.
The Obama administration argues the insurance mandate is critical to the success of health care reform because getting everyone insured is key to bringing down costs.
The ruling marked the first successful court challenge to any portion of the new law, following two earlier rulings in its favor by Democratic-appointed judges. A number of other lawsuits were dismissed early on, without rulings on the substance of the law.
But Hudson denied Virginia's request to strike down the law in its entirety or block it from being implemented while his ruling is appealed by the Obama administration.
Another judge in Florida, a GOP appointee, has not ruled in another lawsuit - brought by 20 states against the legislation - though he has signaled trouble for the administration. Arguments in that lawsuit, which also challenges whether the federal government can require states to expand their Medicaid programs, get under way Thursday in Florida.
Nevertheless, the White House predicted it would prevail in the Supreme Court.
"Keep in mind this is one ruling by one federal district court. We've already had two federal district courts that have ruled that this is definitely constitutional," President Barack Obama said Monday in an interview with television station WFLA in Tampa, Fla.
"You've got one judge who disagreed. That's the nature of these things."
On CBS' "The Early Show" Tuesday, Sen. Dick Durbin, D-Ill., supported the law's constitutionality, and pointed out that this was the third court ruling on the health care reform law. "The first two said it was fine, it was constitutional, so clearly there's a difference even among the Virginia federal courts."
He also chided Republicans who issued a call to repeal the law once they take control of the House of Representatives. "When Eric Cantor and the Republican side says 'Let's repeal 'Obamacare,' he wants to repeal the protection Americans want against the discrimination against them for pre-existing conditions.
"I think that's a losing political position," Durbin said.
Durbin said despite the judge's ruling, the law must proceed.
"Absolutely," he told anchor Harry Smith. "Let me tell you, there are people who will see the protection of health insurance for the first time in their lives. Over 50 million Americans had no health insurance. Sixty percent of them will receive health insurance protection.
"If the Republicans want to repeal the reach and protection of health insurance, it's a great issue, but I'm afraid it's not going to be very kind to the people who are being discriminated against today."
Federal appeals courts based in Atlanta, Cincinnati and Richmond make up the next set of judges who will have their say on the law, though their rulings are at least months away.
Once appellate judges have weighed in, the next appeal is to the Supreme Court.
In April, Justice Stephen Breyer predicted an eventual high court hearing for the health care overhaul. That might not happen until after the 2012 elections, though.
In the short term, the latest court ruling hands potent ammunition to GOP opponents as they prepare to assert control in the new Congress with promises to repeal the law. Mr. Obama in turn has vowed to veto any repeal legislation and appears likely to prevail since Democrats retain control of the Senate. Republicans also have discussed trying to starve the law of funding.
Whatever the eventual outcome, Monday's ruling could create uncertainty around the administration's efforts to gradually put into effect the landmark legislation extending health coverage to more than 30 million uninsured Americans. And it can only increase the public's skepticism, which has not significantly receded in the months since the law's enactment, defying Mr. Obama's prediction that it would become more popular as Americans got to know it.
Mr. Obama aides said implementation would not be affected, noting that the individual insurance requirement and other major portions of the legislation don't take effect until 2014. Some provisions of the law took effect in September, six months after its passage, including free preventive care, an elimination of lifetime limits on coverage and requirements for insurers cover children with pre-existing health conditions and allow adult children to stay on their parents' health plans until age 26.
Hudson limited his ruling to striking down the so-called individual mandate, leaving intact other portions of the law. But administration officials and outside analysts agree that important provisions of the legislation could not go forward without the requirement for everyone to be insured. That's because insurers need to have large pools of healthy people, who are cheap to insure, or it is not financially tenable for them to extend coverage to those with pre-existing medical problems.