Civil liberties advocates brand as unconstitutional a new Ohio law that gives police more leeway than most states to force a blood or urine test on certain drunken driving suspects.

A story from the AP says, under the law that took effect Tuesday, authorities in Ohio can force drivers who have two or more drunken driving convictions to submit to such tests without their consent.

The state previously required authorities to get a warrant from a judge to test blood or urine for alcohol or drugs from people who don't initially give their consent.

"We do believe this law is unconstitutional, especially the part that basically says police don't have to have a warrant," said Jeffrey Gamso, legal director of the American Civil Liberties Union of Ohio. "That's just wrong and a complete misunderstanding of what the U.S. Supreme Court has ruled."

State Sen. Timothy Grendell, the Chesterland Republican who sponsored the legislation, said that a 5-4 decision by the Supreme Court in 1966 supports the law. He said the court ruled that authorities could compel a driver suspected of drunken driving to give a blood sample.

Gamso argues that the court said in that case that it would allow taking of blood from a driver when police had probable cause and authorities could not get a warrant in time to test the blood before signs of alcohol would have disappeared.

"This law is saying that it's a general rule not to have to get a warrant and that is not what the court said," Gamso said. "Warrants are there to protect us from overreaching by the police."

Click here to read more of this story from the AP.