Davis was opposed to slavery and its extension into the territories, but he voted for most of the provisions of the Compromise of 1850, including the bill on Texas borders, shocking some anti-compromise Whigs. He regularly voted in favor of the Wilmot Proviso, a measure to ban slavery from territories won in the Mexican war which was frequently attached to legislation in the late 1840s but was never adopted. In one notable debate, Davis used procedural measures to delay vote on an amendment to remove it from a military appropriations bill, hoping to force a vote without time to conference on differences between the House and Senate versions before Congress adjourned. However, due to a difference in the clocks in the respective chambers, the House adjourned before he finished speaking, scuttling the bill. Salmon P. Chase wrote of the episode, "Ten political lives of ten John Davises, spent in the best direction, could not compensate for this half-hour's mischief", and Polk noted that if the loss of the bill delayed the end of the Mexican war, Davis would "deserve the execrations of the country." Scholarship is divided on whether Davis's claimed strategy would really have worked.