In the months leading up to the Civil War, he became the only governor of a Southern state to oppose secession. When Texas voted to secede, Houston accepted the decision but refused to swear allegiance to the new Confederate States of America. In response, the Texas convention removed him from office and replaced him with Lt. Gov. Edward Clark. Houston always characterized himself as a Southern man for the Union and opposed any threats of disunity, whether from Northern or Southern agitators. He incurred the permanent wrath of proslavery elements by supporting the Compromise of 1850, a series of measures designed to ensure sectional harmony.His career in the Senate was effectively ended when, in 1855, the Texas legislature officially condemned his position on the Kansas-Nebraska Act.Houston ran for governor of Texas in 1857. He was defeated in a rigorous campaign by the state Democratic Party official nominee, Hardin R. Runnels. Predictably, the state legislature did not reelect Houston to the Senate; instead, in late 1857, it replaced him with John Hemphill. Houston ran a second time for governor in