Rep. Tim Ryan (D-Ohio) said Friday that he will not challenge Sen. Rob Portman (R) in 2016, ending months-long speculation that he might enter the race.

"Today, after much thought and deliberation, I am announcing my decision not to run for the United States Senate in 2016," said Ryan in a statement. "With my new and growing family, I feel now is the time to be close to home."

Ryan was viewed as a capable Democrat who would have been a serious contender for his party's nomination. The only Democrat currently in the race is P.G. Sittenfeld, a less well-known Cincinnati councilman.

The big question continues to be whether former governor Ted Strickland (D) will wage a campaign. Strickland is seen widely as Democrats' best possible option against Portman, a well-funded senator who is already gearing up for reelection in his swing state.

Strickland is expected to announce a decision soon.

Democrats must gain at least four seats to win back the Senate majority in 2016. They see Ohio as a top priority in the battle.