Story highlights Mandel was touted as a contender to challenge Democratic Sen. Sherrod Brown

Mandel cited his wife's health in dropping out

Washington (CNN) Ohio Republican Josh Mandel is dropping his bid to unseat Democratic Sen. Sherrod Brown, citing a health issue his wife is facing.

Mandel's decision -- announced in an email to supporters Friday -- means Republicans have suddenly lost their leading candidate in a state President Donald Trump won by 9 percentage points in 2016.

The GOP controls the Senate 51-49, and although more Democrats are at risk than Republicans this year, Trump's national unpopularity means Democrats have a chance of taking control.

"We recently learned that my wife has a health issue that will require my time, attention and presence. In other words, I need to be there," Mandel, the Ohio state treasurer, said in the email.

"Understanding and dealing with this health issue is more important to me than any political campaign. For as long as that takes, whether it is months or years, it is important that I heed my dad's advice and be there for my wife and our kids," Mandel wrote. "After recent discussions with our family and healthcare professionals, it has become clear to us that it's no longer possible for me to be away from home and on the campaign trail for the time needed to run a US Senate race."

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