It’s a simple concept… Left … Right… Democrat or Republican…
Leading up to, during and immediately after the civil war, all the glue sniffers were Democrats. As the glue sniffers left the Democratic Party, to join the Republican Party, all the non glue sniffers left the Republican Party to join the Democratic Party and today all the glue sniffers are in the Republican Party and the non glue sniffers are Democrats.
Here's A Thing... 