El Draque, your last statement has no sense
Sure the dems were the ones who owned every slave (reason i know this, is the republicans were created to combat slavery ), and sure the dems fought against Universal suffrage (rich republican woman is reason that movement started), and yes, the southern demarcates started the KKK and yes, the southern demarcates enacted the Jim Crow Laws, and yes most of the dems voted against the republicans civil rights act, but it looked like they were finally getting there stuff together in the early 2000's, but now they are just as divisive as ever. As and independent, Its disappointing.
it doesn't mean that if republicans were created to fight slavery, that the opposition was necessarily democrat. In the 1800s there was the Republican-Democrat party which divided in a new party called Republicans and the old party Republican-Democrats. This doesn't mean that the new Republicans were against Democrats lol they were not really separated. The republicans had the north and republican-democrats the south, republicans just wanted to abolish slavery, maybe on economical and political ground they had same ideas as the republican-democrats.
Nowadays it is the opposite, Democrats are more politically similar to the old Republicans of 1800 and viceversa. Republicans nowadays are more conservative on social and on economical concepts, while democrats are more liberal (or even interventionists via public expenditures) on political, social and economical matters.
So don't confuse names with history Old republicans of 1800 left the party to abolish slavery, this doesn't mean they were politically close to left conceptions as the new deal of roosevel or obamacare.
According to me, one of the biggest problem in your two-party political system is that americans tend to mix topics. Categories as social views, economical views, religious views, ...
But in USA you can have democrats who are generally more left sided on economical ground but at the same time some more right sided in social views (more "racists", more preference to the resident) than others who promote equality.
I am swiss and i see this very well. Here we have several parties covering all the topics in different ways, so we can define "precisely" every politician. For example we have the socialist party very left sided economically and left sided on sociality (promoting gov intervention in economy and social equality) but at the same time there is a "church" party promoting left sided economic policies but they are very conservative on the social ground (against gay marriages, ...). Same on the right side, some parties very liberal on economic and social ground, some extreme-right who are conservative on everything. In this way we can "categorize" better people and ideas.
In USA honestly i have never understood who is who. We always see democrats as left sided but when you analyze Obama he was maybe left sided on sociality (even if he started to close southern borders and to move migrants) but he was also sometimes very conservative in economics and also very left sided with obamacare. Same for Trump, very conservative on sociality but on economics he is also very interventionist by funding some gov departmenents as the army (gov intervention is a very left sided vision) but at the same time he wants to lower taxes, very liberal view (and not so coherent but ...)