Lincoln launched the Civil War unilaterally, without Congressional action, following the secession of seven Southern states. Only later did he obtain Congressional approval. His critics called him a dictator. He was the first to trample the constitution but is generally considered a great president.
Wilson asked for and received near dictatorial powers from Congress when attacks by Germany against American ships and submarines plunged the nation into World War I. He had to raise and equip a large army to fight on foreign soil. To do so, he demanded and received unprecedented new power and authority. At least he asked congress first.
When Franklin Roosevelt was inaugurated in 1933, the world-wide Great Depression had reached its depths. The new President promised action, and during his first 100 days he enacted expenses that far exceeded his presidential power, afterward when he was challenged by the supreme court he threatened to appoint more judges until he could override their decisions but Congress gave him what he needed to enable him to use federal powers to rout the Depression and rescue every sector of the economy, as well as state and local government, from economic ruin. He further limited state's rights with the "new Deal".
Later, following the 1941 attack on Pearl Harbor, which forced the United States into World War II, FDR's exertion of his presidential powers would far exceed anything Wilson or Lincoln had done. Through the strength of his personality, Roosevelt lead the nation from that day of "infamy" through battles in Europe, Africa, Asia and the Pacific to total victory.
While FDR continued to ask Congress for what he needed, he gave them no choice as to whether they would accede. For example, in demanding that Congress repeal provisions in the Price Control Act (prohibiting ceilings on certain food products), he told the Congress: "In the event the Congress should fail to act, and act adequately, I shall accept the responsibility, and I will act." And he reminded the Congress: "The President has the power ... to take measures necessary to avert a disaster which would interfere with winning of the war." Once again a president trampled the constitution and was looked upon as it's savior.
These are the worst of the presidents as far as following their oath to protect and preserve the constitution. They each believed that the country was more important than the constitution - it is not!
