A federal judge on Friday struck down Ohio's law barring people from knowingly or recklessly making false statements about candidates in a case that the U.S. Supreme Court said needed to be heard.

U.S. District Court Judge Timothy Black ruled that Ohio's law is unconstitutional and prohibited the Ohio Elections Commission and its members from enforcing the law.

The judge said in his ruling that the answer to false statements in politics "not to force silence, but to encourage truthful speech in response, and to let the voters, not the government, decide what the political truth is."

The Supreme Court in June found unanimously that an anti-abortion group should be able to challenge the law, in a case that grew out of a 2010 congressional race. The Susan B. Anthony List has contended that the Ohio statute violates free speech rights and chills a wide variety of political speech.

The case began after then-U.S. Rep. Steve Driehaus filed a complaint when the group planned to post billboards claiming the Democrat's support for President Barack Obama's health care overhaul equated with support for abortion, even though he opposed abortion. The billboard owner declined to post the ads, fearing legal action.

Driehaus then dropped his case after he lost his bid for re-election to a second term.

"After four years and a trip to the U.S. Supreme Court, today we finally have a victory for free speech," Marjoried Dannenfelser, president of the Anthony List group, said in a statement Thursday.

The Ohio Attorney General's Office had no immediate comment Thursday, spokesman Dan Tierney said.

Black had said earlier that the Anthony List group didn't have standing to sue because it didn't suffer any harm, and an appeals court agreed.

But the Supreme Court, without ruling on the constitutionality of Ohio's law, said the challenge should be considered because of the likelihood of future statements that could be called prohibited by the law. The anti-abortion group plans to criticize members of Congress in the mid-term if they voted for the health care legislation, contending that backers support taxpayer-funded abortion.

The Susan B. Anthony List said it wanted a court order so that it could inform voters without fear of prosecution.

Ohio's attorney general, Mike DeWine, said his office defended the constitutionality of the law, although the Republican incumbent had his own significant First Amendment concerns about it.

Some liberal groups also have criticized the law. More than a dozen other states have similar laws.

In reversing the lower federal courts in Ohio, Supreme Court Justice Clarence Thomas wrote "there is every reason to think that similar speech in the future will result in similar proceedings, notwithstanding SBA's belief in the truth of its allegations."

At least 17 states had similar laws at the time of the Supreme Court ruling.