The Supreme Court appeared doubtful of the constitutionality of an Ohio law aimed at stopping false accusations made against political candidates during campaigns.

During oral arguments Tuesday on a key free speech case, most justices seemed willing to allow anti-abortion group Susan B. Anthony List to proceed in its First Amendment challenge against former Rep. Steve Driehaus.

Justice Anthony Kennedy suggested the Ohio law could stifle constitutionally guaranteed debate during political campaigns.

"Don't you think there's a serious First Amendment concern with a state law that requires you to come before a [state elections] commission to justify what you are going to say?" Kennedy said.

Justice Antonin Scalia suggested that even if a false accusation under the law is "minimal" and likely to be later dismissed, "you are forcing them … to go through this procedure in the midst of an election campaign."

The case centers on a dispute between Driehaus and the Susan B. Anthony List, which waged an aggressive attack on the Ohio Democrat's failed re-election bid in 2010.

The group aired radio ads and tried to post billboards in Driehaus' Cincinnati-area district accusing him of supporting "taxpayer-funded" abortions when he voted for President Obama's Affordable Care Act months earlier.

The Ohio Democrat filed a complaint with state election officials that the radio ads and signs were illegal under Ohio’s "false statements" law. The billboard company, not wanting to be added to the complaint, refused to put up the signs.

The Susan B. Anthony List challenged the state law governing false claims as unconstitutional, saying it violated its First Amendment free-speech rights.

Michael Carvin, an attorney representing the group, said that giving the Ohio election board the power to determine what can and cannot be said during political campaigns amounts to a de facto "Ministry of Truth."

"We think that if the commission is going to drag us in front of them to justify our political speech to a bunch of state officials … that is … unconstitutional," he said.

The justices seemed concerned that cases of false accusation wouldn't be resolved until long after an election is over, denying the accuser a voice during the campaign.

"They're brought before the commission, they have to answer this charge that they lied, that they made a false statement. And just that alone is going to diminish the effect of their speech because they have been labeled false speakers," Justice Ruth Bader Ginsburg said.

Chief Justice John Roberts also suggested the law can intimidate third parties, such as billboard companies, newspapers and radio and TV stations, from accepting political ads — as happened with the Susan B. Anthony List.

"Other people are going to be intimidated from helping [groups and individuals] engage in their political speech," he said. "They need third parties to help carry out their message … and the slightest whiff of, 'oh, this is going to be legal trouble,' they say, 'forget about it.'

Ohio Attorney General Mike DeWine hasn't taken a position on the case. And while his state's false statement law has survived legal challenges in years past, the Supreme Court's ruling in a 2012 First Amendment case has left him with "serious concerns about the constitutionality" of the law, according to his amicus brief.

The American Civil Liberties Union, which filed an amicus brief on behalf of the group, called the Ohio law “vague and overbroad" and said it has "chilled" free speech.

The ACLU added the law has caused "significant hardships" for the Susan B. Anthony List because the group has "experienced difficulty finding venues to disseminate its message because vendors are afraid of prosecution under the challenged statute."

The Obama administration also backs the Susan B. Anthony List's argument that the law would stifle "the very type of speech to which the First Amendment 'has its fullest and most urgent application.'"

The administration, however, denies the health care law allows abortions funded by taxpayer dollars.

About one-third of states have similar statutes prohibiting "false" statements made during political campaigns — often, as in Ohio, with criminal sanctions attached.

Driehaus has accused the Susan B. Anthony List of costing him his livelihood and his job in Congress because of the group's attacks against him.

"Not every candidate has millions of dollars to spend on TV ads, and it's difficult to get the truth out, especially when constituents are bombarded with messages," Driehaus said from Swaziland, where he now is a Peace Corps director.

This story was originally published at 2:56 p.m. and since has been updated.