She was elected to a two-year term in the Michigan House of Representatives in 2006 and was subsequently reelected in 2008. Warren chaired the House Great Lakes and Environment Committee since and sat on the Judiciary Committee, the Tax Policy Committee, and the Oversight and Investigations Committee. She also co-chaired the Michigan BioTech Caucus with Republican Senator Randy Richardville.
Warren is an ardent supporter of gender equity and has championed abortion rights. In 2005 she was recognized for her leadership by the National Women's Political Caucus of Michigan with their annual Millie Award. NOW of Michigan named her "Legislator of the Year" in 2009. She has sponsored or cosponsored legislation to prevent pay discrimination, provide emergency contraception, extend family medical leave to adopting parents, and provide support and protections for sexual assault survivors.
Environmental protection
Environmental issues topped Warren's agenda in the state legislature in 2007-2008. She championed the passage of the Great Lakes Compact and associated legislation to govern withdrawals of the state's groundwater. The Center for Michigan touted the package as "the most important accomplishment to come out of the Michigan legislature this year."
Education
Warren and mother-in-law Alma Wheeler Smith introduced legislation in 2009 to provide free college tuition for Michigan residents by raising the state income tax.
2010 State Senate race
In 2010, Warren competed with fellow Democrat Pam Byrnes for the Democratic nomination for the 18th Michigan Senate seat to succeed Liz Brater. Five days before the primary election, an article in a Michigan newspaper revealed that ads for Byrnes and attacking Warren were financed by The Great Lakes Education Project, a Political Action Committee funded in part by Republicans Dick and Betsy DeVos. The Great Lakes Education Project lobbies for choice, accountability and quality in education and assists candidates that support education reform. Warren defeated Byrnes in the primary election with 55.7% of the vote.
Personal life
Until 2017, Warren was married to Washtenaw County Commissioner Conan Smith and was the daughter-in-law of Alma Wheeler Smith.
DUI arrest
On the evening of December 26, 2019, Warren was arrested in Auburn Hills, MI, on suspicion of DUI. Police had received several calls in relation to an apparently impaired driver at approximately 11 p.m. Police dashcam footage showed Warren's Jeep driving erratically and colliding with the right wall of northbound I-75 before continuing on. When finally stopped, Warren told police she was on her way home to Ann Arbor. She also told the arresting officer that she had consumed 2-3 glasses of wine "just a minute ago" and subsequently failed a field sobriety test administered at the scene. Warren refused to take a breathalyzer test and was taken by police to McLaren Hospital in Pontiac where testing showed her blood alcohol level was.21, almost triple the legal limit. Police dashcam footage showed Warren telling police at the scene "You understand there's going to be a moment where we're both going to be on TV", adding "I'm elected. I'm a senator. This is going to be the most famous arrest you've ever made." On February 18, 2020, Warren pled guilty to a reduced charge of misdemeanor driving while intoxicated.
