After his defeat by Lyman Trumbull in the 1856 Senate election, Abraham Lincoln began planning to run against Douglas in the 1858 Senate election. Lincoln strongly rejected proposals to cooperate with Douglas against Buchanan, and he won the Republican nomination to oppose Douglas. Accepting the nomination, Lincoln delivered his House Divided Speech, saying "A house divided against itself cannot stand. I believe this government cannot endure, permanently half slave and half free. I do not expect the Union to be dissolved—I do not expect the House to fall—but I do expect it will cease to be divided. It will become all one thing, or all the other." Douglas rejected Lincoln's notion that the United States could not continue to be divided into free states and slave states, and warned that Lincoln called for "a war of secession, a war of the North against the South, of the free states against the slave states".