In the summer of 1864 a growing number of politicians in the north began to criticize Abraham Lincoln for not negotiating a peace deal with Jefferson Davis. Even former supporters such as Horace Greeley, editor of the New York Tribune, accused him of prolonging the war to satisfy his personal ambition. Others on the right, such as Clement Vallandigham, claimed that Lincoln was waging a "wicked war in order to free the slaves". Fernando Wood, the mayor of New York, began advocating the city should secede from the Union. Vallandigham and Wood joined forces to form the Peace Democrats (Copperheads).