The hotly contentious issue surfaced in the presidential campaign Thursday after the Supreme Court ruled that Americans have a constitutional right to own guns and.
McCain, the Republican presidential nominee-in-waiting, heralded the justices' action as "a landmark victory for Second Amendment freedom."
Voicing a stance that could help him woo conservatives and libertarians, McCain said, "This ruling does not mark the end of our struggle against those who seek to limit the rights of law-abiding citizens. We must always remain vigilant in defense of our freedoms."
His Democratic rival, Obama, issued a more carefully worded statement apparently aimed at both moderate voters and his liberal base. The statement from Obama, who has long said local governments should be able to regulate guns, did not specifically say whether Obama agreed with overturning the specific D.C. ban. But he said Thursday's ruling "will provide much-needed guidance to local jurisdictions across the country."
"I have always believed that the Second Amendment protects the right of individuals to bear arms, but I also identify with the need for crime-ravaged communities to save their children from the violence that plagues our streets through commonsense, effective safety measures," Obama said.
Obama said his view was supported by the court's ruling that the Constitution does not permit "the absolute prohibition of handguns." That language "reinforces that if we act responsibly, we can both protect the constitutional right to bear arms and keep our communities and our children safe," Obama said.
Both presidential candidates endorse an individual's right to bear arms. But they strongly differ beyond that. McCain has had a mostly conservative record on the issue; Obama, a mostly liberal record.
Other than a few departures, McCain is largely in line with the National Rifle Association's hardline support for gun rights. He voted against a ban on assault-style weapons and for shielding gun-makers and dealers from civil damage suits. But he broke with the NRA to favor requiring background checks at gun shows and has taken heat for pushing through campaign finance legislation that gun-rights advocates say muzzled their free speech.
Obama has voted to leave gun-makers and dealers open to lawsuits. He also took largely liberal positions on gun laws while in the Illinois legislature, including backing a ban on all forms of semiautomatic weapons and tighter state restrictions generally on firearms.
Campaigning in Cincinnati, McCain claimed Obama has reversed course on the issue. Obama told FOX Business Network that he's been consistent.
The Democrat's campaign said a spokesman made an "inartful" statement when he said in November that Obama believed the D.C. law was constitutional. But Obama himself did not correct a debate moderator who repeated the position in February.
"You said in Idaho recently, I'm quoting here, 'I have no intention of taking away folks' guns.' But you support the D.C. handgun ban and you've said that it's constitutional," said the moderator, Leon Harris of Washington television station WJLA. Obama nodded as Harris spoke, nodding and saying, "Right, right."
"How can you reconcile those two different positions?" Harris asked.
Obama answered that the United States has conflicting traditions of gun ownership and street violence that results from illegal handgun use. "So, there is nothing wrong, I think, with a community saying we are going to take those illegal handguns off the streets," Obama said.
The Obama campaign argued that Obama was simply acknowledging the question by saying "right."
In other instances, Obama refused to articulate a position when asked whether he thought the D.C. ban was constitutional.
The campaign would not answer directly Thursday when asked whether the candidate agreed with the court that the D.C. ban was unconstitutional, simply pointing back to his statement.
The gun ruling was not the only one from the Supreme Court this week to get the candidates' attention. On Wednesday, both candidates said they disagree with the court's decision, a crime he said states have the right to consider for capital punishment.
"I have said repeatedly that I think that the death penalty should be applied in very narrow circumstances for the most egregious of crimes," Obama said at a news conference. "I think that the rape of a small child, 6 or 8 years old, is a heinous crime and if a state makes a decision that under narrow, limited, well-defined circumstances the death penalty is at least potentially applicable, that that does not violate our Constitution."
The court's 5-4 decision Wednesday struck down a Louisiana law that allows capital punishment for people convicted of raping children under 12, saying it violates the Constitution's ban on cruel and unusual punishment.
McCain, also criticized the court's decision, calling it "an assault on law enforcement's efforts to punish these heinous felons for the most despicable crime."
"That there is a judge anywhere in America who does not believe that the rape of a child represents the most heinous of crimes, which is deserving of the most serious of punishments, is profoundly disturbing," McCain said in a statement.
Obama, the likely Democratic presidential nominee, said that had the court "said we want to constrain the abilities of states to do this to make sure that it's done in a careful and appropriate way, that would have been one thing. But it basically had a blanket prohibition and I disagree with that decision."
The court on Thursday also struck down the "millionaire's amendment," a campaign finance law intended to level the field for House candidates facing wealthy opponents who spend lots of their own money.
The law says that when candidates spend more than $350,000 from their own pockets, opponents may qualify to accept larger individual contributions than normally allowed and can receive unlimited coordinated party expenditures.
The justices, in a 5-4 ruling that reflects skepticism of campaign finance overhauls, said the law violates the First Amendment.
"We have never upheld the constitutionality of a law that imposes different contribution limits for candidates who are competing against each other," Justice Samuel Alito wrote for the majority.
McCain, the co-author of the 2002 campaign finance reforms that contain the provision, expressed no interest in having Congress address the court's decision.
McCain said the decision does not affect the court's landmark ruling upholding the constitutionality of the soft-money ban prohibiting six-figure donations to political parties.
"Today's Supreme Court decision in Davis v. FEC does not affect the Court's landmark ruling in McConnell v. Federal Election Commission upholding the constitutionality of the soft money ban contained in BCRA," McCain said in a statement. That ban is at the core of the reforms I worked for in the long bipartisan fight to pass campaign finance reform."
McCain said the millionaire's amendment was not part of the original legislation and was added on the floor during debate. The other co-author of the reforms, Sen. Russ Feingold, D-Wis., made the same point.
At least 19 House candidates and nine Senate candidates have spent $350,000 or more of their own money on their campaigns so far this election cycle, according to figures from the Center for Responsive Politics, a Washington-based group that tracks political campaign money. In the 2006 elections, the number was 52 candidates.