Knight was angry at Featherston for the constitutional amendment that removed the ban on presidents running for more terms; he had hoped to be elected president in his own right in November 1939, and was bitter when the amendment upset his plans. He was also bitter over being sidelined into the useless slot of vice president while other Freedom Party members, such as Ferdinand Koenig, were given important roles such as attorney general.
The vice president suborned some like-minded stalwarts and convinced them to ambush Featherston's motorcade as it traveled through the streets of Richmond. To entrap Featherston's vehicle, they set up a fake car accident in his path; when the president's outriders stepped down from their motorcycles to push the wreck out of their way, the stalwarts raced out of their hiding spots and opened fire with submachine guns at Featherston's car, killing his driver Virgil Joyner in the process. The president and his bodyguards killed off the stalwarts and managed to get back to the Gray House.
In due course, Knight's role in the plot was uncovered; the vice president was forced to resign after being impeached and found guilty in the Freedom-controlled Confederate Congress and Senate. Upon leaving his office, the ex-vice president was arrested by a squad of Freedom Party Guards and sent to the cellars of the Justice Department, where he was tortured by Ferdinand Koenig's henchmen. Then Knight was dispatched in great secrecy to Louisiana, where he was incarcerated in Jefferson Pinkard's Camp Dependable, where he was murdered soon after the outbreak of war in 1941.
The December Plot allowed Jake Featherston to remove a quarrelsome political rival from office. At the Freedom National Convention in the summer of 1939, the slot of vice president was taken by Tennessee senator Don Partridge, who was a staunch Freedom man and politically harmless. The Featherston-Partridge ticket won the November election in a (rigged) landslide, and Featherston was safe from future intra-party strife.
The plot also had the effect of virtually reducing the stalwarts role in Confederate society and Freedom politics; their duties were taken by the guards, and soon the stalwarts more or less vanished, with most of their number being conscripted into the Confederate Army in the spring of 1940.