Fillmore was embittered when Weed got the nomination for Seward but campaigned loyally, Seward was elected, and Fillmore won another term in the House.[44]
The rivalry between Fillmore and Seward was affected by the growing anti-slavery movement. Although Fillmore disliked slavery, he saw no reason for it to be a political issue. Seward, however, was hostile to slavery and made it clear in his actions as governor by refusing to return slaves claimed by Southerners.[44] When the Buffalo bar proposed Fillmore for the position of vice-chancellor of the eighth judicial district in 1839, Seward refused, nominated Frederick Whittlesey, and indicated that if the New York Senate rejected Whittlesey he still would not appoint Fillmore.[45]
Fillmore was active in the discussions of presidential candidates which preceded the Whig National Convention for the 1840 race. He initially supported General Winfield Scott but really wanted to defeat Kentucky Senator Henry Clay, a slaveholder who he felt could not carry New York State. Fillmore did not attend the convention but was gratified when it nominated General William Henry Harrison for president, with former Virginia Senator John Tyler his running mate.