The 45-year-old former Posey County prosecutor filed his papers Friday at the Indiana secretary of state's office after incumbent Brad Ellsworth said he'd seek the Senate vacancy created when Evan Bayh announced he won't run again.
Van Haaften filled a vacant Indiana House seat in 2004 and was elected to the seat later that year. He's chaired the House Public Policy Committee as it wrestled with alcohol and gambling legislation.
National Republican Congressional Committee spokesman Tom Erickson says Van Haaften is "squishy on abortion" and supports tax increases. Six Republicans are seeking their party's nomination in the 8th District.