In his fine Fugitive Justice: Runaways, Rescuers, and Slavery on Trial, Steven Lubet describes Salmon Portland Chase's brush with nullification.
On Monday September 13, 1858, slave catchers seized a runaway slave by the name of John Price near Oberlin, Ohio and conducted him to the nearby town of Wellington, whence they planned to take a train to Columbus. Unbeknownst to them, Oberlin opponents of the Fugitive Slave Act of 1850 learned of the event and followed them. The slave catchers found themselves besieged in a Wellington hotel by a mixed-race crowd of 300 to 500 people demanding Price's release. In brief, members of the crowd stormed the hotel and transferred Price to a carriage. Price ultimately escaped to Canada.
On December 6, 1858, a federal grand jury in Cleveland indicted thirty-seven men for violation of the Fugitive Slave Act. Two of the defendants were tried and convicted in April and May 1859. A number of others were remanded to custody pending their trials.
In mid-May, however, the convicted defendants' attorneys filed a petition for habeas corpus with the Ohio Supreme Court, which scheduled argument for May 25, 1859.
Supporters of the defendants held a massive rally in Cleveland on May 24. By some estimates, as many as twelve thousand people attended. Although he had long been a leader in the anti-slavery movement, Governor Salmon P. Chase had not spoken out in connection with this or several previous incidents involving the Fugitive Slave Act and was not scheduled to attend. But perhaps because his earlier silences had been the subject of criticism he made an unexpected appearance.
Following other speakers who had vowed to resist the Fugitive Slave Act with force if necessary, Chase tried to walk a fine line between denouncing the law and advocating extra-legal measures. But in the end Chase "took a step toward the abyss":
If the process for the release of any prisoner should issue from Courts of the State [of Ohio], he was free to say that so long as Ohio was a Sovereign State, that process should be executed.
"'When the time came,' [Chase] said, 'and his duty was plain, he, as Governor of Ohio, would meet it as a man.'" In short, Chase had vowed to defy the federal government if necessary. "The Oberlin rescuers were still in jail and Governor Chase had all but promised to deploy the state militia on their behalf."
Luckily for Chase, the Ohio Supreme Court rescued him from his reckless commitment. By a 3 to 2 vote the Court denied the habeas petition. Although an abolitionist and a Republican, Chief Justice Joseph Rockwell Swan concluded that he was "bound by my official oath to sustain the supremacy of the constitution and the law:'THE PRISONER MUST BE REMANDED.'"