He insisted that northern abolitionists stand down to avoid a southern secession, writing that the bloodshed of a civil war would "not be along Mason and Dixon's line merely", but "within our own borders in our own streets".[149] He also criticized New England Protestant ministers, who largely supported abolition and Republican candidates, for their "heresy and treason".[149] The rise of the Republican Party forced the Democrats to defend Pierce; during his debates with Republican Senate candidate Abraham Lincoln in 1858, Douglas called the former president "a man of integrity and honor".[152]
As the Democratic Convention of 1860 approached, some asked Pierce to run as a compromise candidate that could unite the fractured party, but Pierce refused. As Douglas struggled to attract southern support, Pierce backed Cushing and then Breckinridge as potential alternatives, but his priority was a united Democratic Party. The split Democrats were soundly defeated for the presidency by the Republican candidate, Lincoln. In the months between Lincoln's election, and his inauguration on March 4, 1861, Pierce looked on as several southern states began plans to secede. He was asked by Justice Campbell to travel to Alabama and address that state's secession convention. 