What is Abraham Lincoln's biggest fear politically?
Lincoln's greatest fear politically was that he would be the last president of the United States of America--that the Confederate states would win their war for secession and that the Republic would collapse into a collection of micro-states. Lincoln was willing to bend the rules of the Constitution--he suspended the writ of habeas corpus several times during the war to persecute Rebel sympathizers. He authorized his armies to wage war against civilians in order to bring the states in rebellion under control. He ignored pleas from his own party to free the slaves outright--the amendment which freed the slaves was only ratified upon his death in 1865. Lincoln knew that he was not politically popular and did little to grow his party base or to make himself more re-electable in 1864; rather, he acted according to his conscience and kept the nation together as he swore to do when he took the oath of office.
Lincoln’s greatest political fear was that the schism fronted by abolitionists was likely to divide the country into slaveholding and non-slaveholding states. Passage of the Kansas-Nebraska Act only served to intensify the abolitionist movement, and although Lincoln supported abolition, he was afraid the tactics being employed threatened national unity. He sought to leave slavery undisturbed in the areas it already existed, but at the same time, he tried to stop its spread.
As he took over the presidency of the United States, his worst fears became manifest; South Carolina officially seceded and was soon joined by other pro-slavery states. After the first shots were fired at Fort Sumter, Lincoln had no choice but to marshal Union troops to arrest the rebellion. After extensive maneuvering by the president, the war was won, and the Union survived.