Eric Foner offers his two cents:
How different is today’s GOP party from the Republican Party of Abraham Lincoln?
It could not be more different. Lincoln in 1860 did not receive a single vote in most of the southern states. His Republican party was the party of opposition to the expansion of slavery and later of emancipation, and a strong federal government protecting the civil and political rights of black Americans. Today the party’s center of gravity is in the South, it opposes most federal initiatives (except defense) and is the inheritor of Richard Nixon’s “southern strategy” aimed almost exclusively at white voters….