In part due to the ongoing violent political confrontations in the Kansas, opposition to the Kansas–Nebraska Act remained strong in Illinois and throughout the North. As the 1856 elections approached, Lincoln abandoned the defunct Whig Party in favor of the Republicans. He attended the May 1856 Bloomington Convention, which formally established the Illinois Republican Party. The convention platform asserted that Congress had the right to regulate slavery in the territories and called for the immediate admission of Kansas as a free state. Lincoln gave the final speech of the convention, in which he endorsed the party platform and called for the preservation of the Union. At the June 1856 Republican National Convention, Lincoln received significant support on the vice presidential ballot, though the party nominated a ticket of John C. Frémont and William Dayton. Lincoln strongly supported the Republican ticket, campaigning for the party throughout Illinois. The Democrats nominated former Ambassador James Buchanan, who had been out of the country since 1853 and thus had avoided the debate over slavery in the territories, while the Know Nothings nominated former Whig President Millard Fillmore. In the 1856 elections, Buchanan defeated both his challengers, but Frémont won several Northern states and Republican William Henry Bissell won election as Governor of Illinois. Though Lincoln did not himself win office, his vigorous campaigning had made him the leading Republican in Illinois.