Jacobs has formed an exploratory committee and has been traveling the state meeting with voters to gauge support for a potential run, and previously met with the National Republican Senatorial Committee to discuss a potential bid.

“I am extremely honored that fellow Iowans believe I am the type of leader who could effectively represent our state,” he said in a statement.

“It is clear that our country is on the wrong track, and we need fresh perspective in Washington. From what I’ve already heard, there is strong interest in electing leaders with real-life business experience and sound conservative principles to get things done."

Davis, the former president and CEO of Texas-based Reliant Energy, moved back home to Iowa last year and launched an education advocacy group.

He'll join a handful of already-declared candidates, including talk-radio host Sam Clovis, U.S. Attorney Matt Whitaker, and David Young, who formerly served as Sen. Chuck GrassleyCharles (Chuck) Ernest GrassleySenators push mandatory sexual harassment training for members, staff Senate panel to hold hearing on bump stocks, background checks Senate panel to hold hearing on bump stocks MORE's (R-Iowa) chief of staff, in the Republican primary. State Sen. Joni Ernst is expected to run for the seat as well.

Rep. Bruce BraleyBruce BraleyOPINION | Tax reform, not Trump-McConnell feuds, will make 2018 a win for GOP Ten years later, House Dems reunite and look forward Trump: Ernst wanted 'more seasoning' before entertaining VP offer MORE (D) is running for, and expected to easily nab, the Democratic nomination.

A poll released earlier this month indicated the three Republican candidates polled — Whitaker, Ernst and Young — are relatively unknown, with a majority of those surveyed reporting they don't have enough information about the candidates to make a judgment on them.