Many of Lincoln's "public" anti-slavery sentiments were presented in the seven Lincoln–Douglas debates of 1858 against his opponent, Stephen Douglas, during Lincoln's unsuccessful campaign for a seat in the U.S. Senate (which was decided by the Illinois legislature). Douglas advocated "popular sovereignty" and self-government, which would give the citizens of a territory the right to decide if slavery would be legal there. Douglas criticized Lincoln as being inconsistent, saying he altered his message and position on slavery and on the political rights of freed blacks in order to appeal to the audience before him, as northern Illinois was more hostile to slavery than southern Illinois.