History, for those who care to know the truth, shows that the Republicans were the "anti-slavery" party and always have been. Lots of facts here to sink your teeth into.
There are those who believe that the Segregationists/Democrats joined the Republican Party after the Civil Rights Act. This too is a convenient fabrication. The second video, reveals the truth about the switching of parties. Kebreau says:
Most Americans believe that the political parties switched shortly after the Civil Rights Act of 1964-The Landmark Anti-Discrimination Law. As the story goes, the Democrats became Republicans in protest of their party apparently supporting Civil Rights for Blacks. In truth, the vote count for the Civil Rights Act of 1964 was 80% Republican support to 63% Democratic Party support. So either the Democrats who did not support this Law left the Democratic Party or their constituents stopped voting for Democrats and elected Republicans. Politics is about Power and Power only comes from the votes cast by your power base. Let's see how it turned out.