Positioning herself as a "tenacious fighter" who will "challenge the system," Lt. Gov. Mary Taylor formally announced her candidacy for the Republican nomination for governor Friday.

Speaking at the City Club of Cleveland, Taylor said Ohio as a state has "dug ourselves out of a hole" during 6 1/2 years she's served as lieutenant governor to Gov. John Kasich. "We have made progress in important areas. But there is much work yet to be done," she added.

Taylor, 51, enters a field crowded with three other Republican officeholders: Attorney General Mike DeWine, Secretary of State Jon Husted and U.S. Rep. Jim Renacci of Wadsworth. They are vying for the chance to succeed Republican Gov. John Kasich who cannot run for re=-election next year due to term limits. Four Democrats also are running for governor.

She mentioned Kasich just once in her speech, calling him "a good man ... I learned that a caring heart is essential to being a great leader."

Although she has been part of state government since 2003, Taylor said, "I am eager for this campaign to begin, to challenge the status quo."

"This race will not be easy but that's just fine with me, because nothing important has ever come easily in my life," Taylor said. "I am not the product of a life of privilege ... When I was in middle school, my mother left us so I was raised by my father and grandmother. My dad was a blue-collar worker."

While Taylor touched on several topics, including improving the state's business environment, "resetting" the charter school system, and providing temporary relief" but not permanent help for Ohioans in poverty, she acknowledged the state's crippling opioid epidemic is the most important issue and one that is personal to her.

She disclosed earlier this year that her two sons, Joe and Michael, have struggled with drug addiction.

"I have known the sorrow that drug addiction causes. I'm angry -- angry at what drug addiction does, the dreams it destroys, and the lives it takes. I'm determined -- determined to fight for the lives of Ohioans from every region, race and economic circumstance who find themselves ensnared in this addiction."

She called for "a comprehensive, fully-integrated drug control strategy -- one that makes use of all the tools available to us, including law enforcement, treatment, education, faith initiatives, public service campaigns, and border interdiction."

Taylor previously served on Green City Council, as a state representative and state auditor. In 2010, she joined the ticket with Kasich and was elected lieutenant governor. Taylor and Kasich were re-elected in 2014.