[245] Though still concerned about slavery, Van Buren and his followers returned to the Democratic fold, partly out of the fear that a continuing Democratic split would help the Whig Party.[246] He also attempted to reconcile the Barnburners and the Hunkers, with mixed results.[247]
Van Buren supported Franklin Pierce for president in 1852,[248] James Buchanan in 1856,[249] and Stephen A. Douglas in 1860.[250] Van Buren viewed the fledgling Know Nothing movement with contempt and felt that the anti-slavery Republican Party exacerbated sectional tensions.[251] He considered Chief Justice Roger Taney's ruling in the 1857 case of Dred Scott v. Sandford to be a "grievous mistake" since it overturned the Missouri Compromise.[252] He believed that the Buchanan administration handled the issue of Bleeding Kansas poorly, and saw the Lecompton Constitution as a sop to Southern extremists.[253]

1858 portrait by GPA Healy, on display at the White House
After the election of Abraham Lincoln and the secession of several Southern states in 1860, Van Buren unsuccessfully sought to call a constitutional convention.