JEFFREY BROWN: Now, a busy day at the high court, and to Judy Woodruff.

JUDY WOODRUFF: A 6-2 ruling from the U.S. Supreme Court today makes it tougher for parents who say their children were injured by vaccines to file lawsuits against drugmakers.

Also at the court today, justices heard arguments in a case that started with an act of revenge and could have implications for the scope of individuals' rights under the 10th Amendment.

Here, as always, to walk us through it, Marcia Coyle of "The National Law Journal."

It's good to have you with us again.

MARCIA COYLE, "The National Law Journal": Thank you, Judy. It's good to be here.

JUDY WOODRUFF: So, let's start with this vaccine injury case. Tell us what the justices ruled.

MARCIA COYLE: The majority, in an opinion by Justice Scalia, said that the federal law, the National Child Vaccine Injury Act, preempts or blocks state lawsuits based on a claim that a vaccine was defectively designed.

The case was brought to the Supreme Court by the parents of Hannah Bruesewitz, who, as an infant, received the diphtheria, pertussis and tetanus vaccine combination. She suffered severe disabling seizures, which she continues to suffer at age 19 today.

JUDY WOODRUFF: Now, this -- this case reminds us that there is another recourse for parents who believe their children have been injured by a vaccine.

MARCIA COYLE: Part of the court's rationale was looking at the fact that Congress, under this act, created a no-fault compensation program.

Parents can file claims of vaccine-related injuries. And if their claim is denied or if the amount of money that they receive is inadequate, they feel, they can still go into court.

But, under today's ruling, they cannot bring a design defect claim, because the court felt the language and structure of the federal law did not suggest that Congress intended these types of claims to be brought.

JUDY WOODRUFF: And, Marcia, this was a case that was watched very -- being watched very closely by vaccine manufacturers. Tell us why.

MARCIA COYLE: It was, Judy, because there are pending a large number of autism vaccine-related claims.

And the manufacturers felt if the court had ruled the other way, that they would be facing hundreds of lawsuits in state courts.

JUDY WOODRUFF: All right, now, let's talk about this case that was argued today before the court. This one has to do with a woman who was convicted of trying to poison a woman friend after the friend, she found out, though, was made pregnant by her own husband.

But it's really a case over the 10th Amendment, but it sounds like a soap opera.

(LAUGHTER)

JUDY WOODRUFF: So, explain it.

MARCIA COYLE: We call it the Lifetime movie case.

(LAUGHTER)

MARCIA COYLE: Carol Bond was a microbiologist in Pennsylvania. And after she discovered her friend was pregnant with Carol Bond's -- by Carol Bond's husband, she engaged in a campaign that started with harassing and threatening letters and phone calls, and escalated to 24 separate attempts to injure her by using toxic chemicals that Bond either stole from her employer or got on the Internet.

Bond was convicted under a federal law, a chemical weapons law that was enacted by Congress to implement a 1993 chemical weapons treaty. She was sentenced to six years in prison.

JUDY WOODRUFF: And so what is the exact question before the court?

MARCIA COYLE: Well, the question for the court really isn't whether this chemical weapons law is unconstitutional.

Bond, in her appeal, wanted to prove that it was unconstitutional, but the lower appellate court said she could not bring this claim, that she didn't have what we call standing. So, the issue before the court is whether Carol Bond can make a claim that the law is unconstitutional, because she argues it exceeds Congress' powers by encroaching on the province of the states, in violation of the 10th Amendment.

JUDY WOODRUFF: And remind us, for all of us who don't study the Constitution every day, even though we should, the 10th Amendment.

MARCIA COYLE: It's a short amendment. The 10th Amendment says powers not delegated to the United States by the Constitution, nor prohibited to the states, are reserved to the states or to the people.

JUDY WOODRUFF: And give us the flavor, Marcia, of the back and forth between the counsels and the justices today.

MARCIA COYLE: Bond is basically saying here that her crime was essentially domestic abuse, and that is a crime that is best handled by local authorities. That is the province of the state, which is why she brings in the 10th Amendment.

Her lawyer said any individual who has an injury that relates -- a specific, concrete injury from Congress exceeding its powers in this respect should be able to bring a claim like Bond has brought under the 10th Amendment.

The government also argued -- and they now changed their position and have said that Bond does have standing to bring this claim, but not all 10th Amendment claims can be brought by individuals, because, the government says, the 10th Amendment also protects state sovereignty. There's a type of 10th Amendment claim that only states can bring.

The justices were somewhat skeptical of the government's argument. The chief justice said he thought it would be awfully hard sometimes for an individual to know where the line is under the 10th Amendment between a claim they can bring and a claim that only a state can bring.

JUDY WOODRUFF: Implications of this are big though, Marcia, 10th Amendment states rights, but also specifically connected to President Obama's health-care reform law.

MARCIA COYLE: There has been at least one federal court that has denied standing to an individual who wanted to challenge the health-care law on 10th Amendment grounds.

The 10th Amendment has enjoyed something of a rejuvenation by certain political groups, particularly conservative groups, groups like the Tea Party, who see it as a tool to fight what they think is unlimited government action.

And you can see this in some of the amicus briefs that were filed in the Supreme Court on behalf of Bond. In fact, six states filed to support her. And they were represented by the same lawyer who is representing the 26 states' attorneys general who are challenging the law in Florida.

JUDY WOODRUFF: So, it's going to be more than soap-opera fans who are watching the results.

MARCIA COYLE: It is. And it may even be more if the court rules broadly for Bond. It's not only the health care law. There may be new litigation by individuals challenging a host of federal laws under the 10th Amendment.

JUDY WOODRUFF: Marcia Coyle, always a pleasure. Thank you.

MARCIA COYLE: My -- my pleasure, Judy.