The hearings call into question an executive order signed last year regarding same-sex marriages, a delayed call for public elections, and the lack of punishment for officials at the state's Department of Public Safety.
The executive order in question allowed the state to accept income tax returns from same-sex couples who were married in other states. According to Republicans, the order violates the state's ban on same-sex unions.
Nixon is a Democrat, and the state House is mostly comprised of Republicans. The impeachment proceedings are not expected to get past the committee level to see a vote on the House floor. This effort is mostly seen as partisan posturing in order for the Republicans to gain the upper hand over the Democratic governor.
Nixon's office has dismissed the efforts as nothing more than a "publicity stunt."