WASHINGTON The Supreme Court appears to be highly skeptical of laws that try to police false statements during political campaigns, raising doubts about the viability of such laws in more than 15 states.

Justices expressed those concerns early and often Tuesday during arguments in a case challenging an Ohio law that bars people from recklessly making false statements about candidates seeking elective office.

The case has attracted widespread attention, with both liberal and conservative groups saying the law tramples on the time-honored, if dubious, tradition of political mudslinging. Critics say free speech demands wide-open debate during political campaigns, including protection for negative speech that may sometimes twist the facts.

The high court is not expected to rule directly on the constitutional issue because the current question before the justices is only a preliminary one: Can you challenge the law right away, or do you have to wait until the state finds you guilty of lying?

But the justices couldn’t resist going after the law itself, pointing out that the mere prospect of being hauled in front of state officials to explain comments made in the heat of an election has a chilling effect on speech.

“What’s the harm?” Justice Stephen Breyer asked Eric Murphy, attorney for the state of Ohio. “I can’t speak, that’s the harm.”

Justice Anthony Kennedy said there’s “a serious First Amendment concern with a state law that requires you to come before a commission to justify what you are going to say.”

The case began during the 2010 election when a national anti-abortion group, the Susan B. Anthony List, planned to put up billboards accusing then-Rep. Steve Driehaus of supporting taxpayer-funded abortion because he voted for President Barack Obama’s new health care law. Driehaus, a Democrat who opposes abortion, claimed the group’s billboard ads distorted the truth and therefore violated the false speech law.

Driehaus filed a complaint with the Ohio Elections Commission, an action that prompted the billboard owner to decline posting the ads. The commission found probable cause that the ads violated the law, but Driehaus later withdrew his complaint after losing his re-election campaign.

The Susan B. Anthony List then challenged the state law as unconstitutional, but a federal judge said the group didn’t have the right to sue because it hadn’t yet suffered actual harm. The 6th U.S. Circuit Court of Appeals in Cincinnati agreed.

Murphy argued that the Susan B. Anthony List has not shown a credible threat of harm because the Driehaus case was ultimately dismissed before it was referred to a prosecutor.

But Justice Elena Kagan wondered why a probable cause determination didn’t count as harm. For the average voter, “they think probable cause means you probably lied,” she said.

Chief Justice Roberts pointed out that third parties such as TV stations or billboard owners are going to be intimidated by the law, preventing a group from getting its message out.

“The slightest whiff of this is going to be legal trouble,” Roberts said.

Justice Antonin Scalia said the Susan B. Anthony List intends to make the same charges against other Democrats in the next election. He said the harm is that the group fears being dragged before the “Ministry of Truth” for similar proceedings, referring to the government propaganda office in George Orwell’s novel “Nineteen Eighty-Four.”

At one point, Murphy reminded the justices that they were not there to debate the merits of the law, just the question of standing. But Breyer said the merits discussion is meant to suggest “that there are real people who would really like to speak in an election campaign. And if they feel they can’t they are really being hurt.”

Michael Carvin, attorney for the Susan B. Anthony List, suggested that election speech has “an extraordinarily short shelf life” and a group accused of false speech will never be able to go through the entire process of being accused of a crime and exonerated before the election is over.

More than 500 false statement claims have been brought under the Ohio law between 2001 and 2010, Murphy told the justices. Only five cases have been referred to a prosecutor, and of those, three resulted in plea agreements.

“So you have a system that goes on and on, year after year, where arguably there’s a great chilling of core First Amendment speech, and yet you’re saying that basically you can’t get into federal court,” Justice Samuel Alito said.

Other states with similar laws include Alaska, Colorado, Florida, Louisiana, Massachusetts, Michigan, Minnesota, Montana, North Carolina, North Dakota, Oregon, Tennessee, Utah, West Virginia and Wisconsin.

The case is Susan B. Anthony List v. Driehaus, 13-193. A ruling is expected by late June.