he Lincoln-Douglas debates of 1859 were a series of seven debates between Abraham Lincoln, a Republican, and Stephen A. Douglas, a Democrat, for an Illinois seat in the United States Senate. At the time, U.S. Senators were elected by state legislatures; thus Lincoln and Douglas were campaigning for their parties to win control of the legislature. The main theme of the debates was the expansion of slavery into the territories.KSk lasndl sjnsj sjnalnd lskdj jd jd jd djd d d d d d dd d d d d d d d d d d d d d dd d d dhe Lincoln-Douglas debates of 1859 were a series of seven debates between Abraham Lincoln, a Republican, and Stephen A. Douglas, a Democrat, for an Illinois seat in the United States Senate. At the time, U.S. Senators were elected by state legislatures; thus Lincoln and Douglas were campaigning for their parties to win control of the legislature. The main theme of the debates was the expansion of slavery into the territories. he Lincoln-Douglas debates of 1859 were a series of seven debates between Abraham Lincoln, a Republican, and Stephen A. Douglas, a Democrat, for an Illinois seat in the United States Senate. At the time, U.S. Senators were elected by state legislatures; thus Lincoln and Douglas were campaigning for their parties to win control of the legislature. The main theme of the debates was the expansion of slavery into the territories. he Lincoln-Douglas debates of 1859 were a series of seven debates between Abraham Lincoln, a Republican, and Stephen A. Douglas, a Democrat, for an Illinois seat in the United States Senate. At the time, U.S. Senators were elected by state legislatures; thus Lincoln and Douglas were campaigning for their parties to win control of the legislature. The main theme of the debates was the expansion of slavery into the territories.