MADISON, Wis. — Two Republican legislators started moving a package of proposals to toughen Wisconsin’s drunken driving penalties through the state Assembly on Thursday, saying lawmakers must signal that repeat offenses won’t be tolerated.

Rep. Jim Ott and Sen. Alberta Darling presented three bills to the Assembly Judiciary Committee during a public hearing. One would change third and fourth offenses from misdemeanors to felonies. Another would create mandatory sentences ranging from six months in jail to three years in prison for injuring someone in a drunken crash. The third would impose a mandatory 10-year prison sentence for killing someone while driving drunk.

The measures carry price tags in the tens of millions of dollars for prosecutors and the state’s prison system. The committee didn’t take any action on the bills and their prospects look uncertain at best.

“The bills before us have merit,” said committee member Rep. Gary Hebl, D-Sun Prairie. “The concerns I have is the fiscal note is almost prohibitive. … It’s a lot of money.”

Ott, R-Mequon, and Darling, R-River Hills, were undaunted, telling the committee the time has come to crack down.

“It’s time we start balancing the scale of justice with what’s happening to the victims,” Darling said.

Drinking is woven into Wisconsin’s culture, leading to major problems on the road. The state Department of Transportation has tracked nearly 2,800 fatal crashes and nearly 40,000 injury crashes involving alcohol between 2002 and last year. Data from the National Highway Traffic Safety Administration shows 23 percent of drivers involved in fatal crashes in Wisconsin in 2011 had a blood-alcohol content of at least 0.08 percent — that’s the highest percentage of drivers in a region that included Illinois, Indiana, Michigan, Minnesota and Ohio.

But the state’s drunken driving laws remain famously lax. Wisconsin, for example, is the only state where a first offense isn’t a crime; it’s treated as a civil violation akin to a speeding ticket. Prohibitive cost estimates and push-back from powerful Tavern League lobbyists have stymied harsher penalties.

The most dramatic changes came in 2009, when Democratic lawmakers pushed through a bill that made a first offense a misdemeanor if a child is in the car. It also made a fourth offense a felony if it occurs within five years of the third offense.

Ott has been pushing for tougher penalties for years, trying to fulfill a promise he made to Judy Jenkins, a constituent whose pregnant daughter and 10-year-old granddaughter were killed in 2008 by a driver who had just been convicted of his third operating while intoxicating offense.

He and Darling worked on several bills last session, but the proposals went nowhere after state agencies estimated the measures would cost tens of millions of dollars a year.

The estimates this time around are just as expensive.

The state Department of Administration projected changing third and fourth offenses to felonies would drive up prosecutors’ costs by $1.1 million annually. The state Department of Corrections projected the change would generate an additional $158.2 million to $226 million in operating costs annually. The agency also said it would have to construct 17 new alcohol treatment facilities at a price of $236.4 million.

Ott, who chairs the committee, insisted the estimates were overblown. Stiffer penalties will deter people from driving drunk, keeping government costs down, he said.

“The purpose isn’t to put more people in prison,” he said. “It’s to change behavior.”

Drunken driving victims’ relatives pleaded with the committee to pass the bills.

Dawn Johnson of Deerfield, a 46-year-old Mothers Against Drunk Driving volunteer, told the committee the drunken driver who killed her father in Sheboygan County in 2011 received a year in jail with work release privileges.

“Our family did not have the opportunity to say goodbye while the drunk driver is free,” Johnson said. “I ask this committee how much is the state of Wisconsin and its taxpayers willing to endure fiscally and emotionally from drunken driving?”

Responded Ott: “I don’t care what it costs to incarcerate someone like that.”

A spokeswoman for Assembly Speaker Robin Vos, R-Burlington, didn’t immediately return an email message seeking comment on the bills. Senate Majority Leader Scott Fitzgerald, R-Juneau, said in a statement that Senate Republicans hadn’t discussed the bills as a caucus yet.