Iowa state Sen. Joni Ernst (R) will run for the Senate in 2014, she announced Wednesday, entering a crowded GOP field vying for retiring Democratic Sen. Tom Harkin's seat.

"As a mother, soldier, and a conservative, the values I hold dear, and have fought more than 20 years to protect, are being threatened by the failed policies of this president," Ernst writes on her campaign Web site. "Washington has failed us. We need and deserve better leadership. And that’s why I am running for U.S. Senate."

Ernst is a former county auditor who has served in the Army Reserves for nearly two decades. She spent more than a year in Kuwait at the beginning of the Iraq war.

The state legislator joins a Republican field that already includes David Young, a former chief of staff to Sen. Chuck Grassley (R); former U.S. Attorney Matt Whitaker; and former conservative radio host Sam Clovis. Retired energy company CEO Mark Jacobs recently took a step toward running, too.

On the Democratic side, Rep. Bruce Braley  appears set to cruise to the nomination.