Some critics of the Dred Scott decision charged that President James Buchanan had conspired with Chief Justice Roger B. Taney to allow further expansion of slavery. Such critics included Abraham Lincoln and other Republicans.
In March 1857, Buchanan announced in his inaugural address that the issue of slavery in the territories would soon be settled. Two days later the Dred Scott decision was announced.
The historical record seems to indicate that Taney, at the very least, did provide advance notification to the president about the court’s decision. Further, it appears that Buchanan, in a clear abuse of his authority, persuaded a Northern Justice to join the Southerners, allowing the decision to appear less regionally partisan.