Worst president ever is probably James Buchanan
To retain the support of Southern Democrats and believing early statehood for Kansas would defuse the explosive territorial problem, Buchanan endorsed a proslavery constitution for Kansas. His fellow Democrat, Senator Stephen A. Douglas of Illinois, challenged this endorsement and instead demanded a legitimate popular vote in Kansas. These Kansas troubles, especially the break with Douglas, divided the Democratic Party and weakened Buchanan.
In 1860, the rift between James Buchanan and Stephen Douglas doomed the political aspirations of both. Under the strain of internal pressure and sectional tension, the Democratic Party finally snapped in two, allowing an unknown railroad lawyer from an upstart party -- the Republican Abraham Lincoln -- to win the White House. The election of a Northerner clearly opposed to the extension of slavery outside existing Southern states frightened the South.
Six weeks after Lincoln's election, South Carolina left the Union, and within another six weeks, six other states followed. Maintaining that he lacked power, the lame-duck Buchanan took no action to stop secession, which only emboldened the new Confederacy and gave seceding states time to set up a government. Buchanan seemed eager to get out of the White House before the real disaster ensued. He vanished from public life and retreated to his home, seeing only close friends until his death in 1868.
So Buchanan lost his party, lost the presidency, and lost the nation and lead to the loss of 500,000 American lives.
Of course, others have other definitions of ever.
