"Lincolon was a republican" ????
You're talking ancient history here.
Trent Lott and Jesse Helms are repubicans, as was Strom Thurmond. Any of those names ring a bell? What are they famous/notorious for? It hasn't been all that long ago that Reps voted against a holiday for MLK. When Bush ran in Florida on Nov. 7, 2000, his brother's state, countless blacks were still denied the right to vote and some were even beaten, tear-gassed, and taken in to jail. It might as well have been 1950, not 2000. Republican poll workers stayed up all night on that election day, "hand-correcting" 30,000 absentee ballots, which mysteriously had a 2-1 ratio of republican-to-democratic votes. No one had a problem with that in Florida, but when a box containing only 230 votes was found in a black church just a few hours after the polls had closed, Florida secretary of state Katherine Harris, who was also Dumbya's campaign manager, disallowed the votes. Or should I say she "terminated them with extreme prejudice."
And then there's the chads. Al Gore is the only candidate who had a problem with hanging, dimpled, pregnant, or double-punched chads. Dubya's were as pure as the driven snow, just like all of this last six years have been for the middle class, the working class, and the poor.
So you're comparing the "oppressive" democratic party of 44-150 years ago to the republican party of Plantation Owners of today and tomorrow, and you're asking why blacks in general embrace the democratic party.
I'd say it's because they're not as stupid and ignorant as white folk who know how deep they have to dig in their pockets for a dime, and still believe we're "more prosperous than we've ever been" just because Dumbya says so. The White House, the Senate, Congress, and the Supreme Court are all republican-controlled, and they have been for awhile now. Quite awhile.
And eight trillion dollars in debt, no taxes from the rich when they die and none on their dividends, not even when these things run in the billions each year for one individual like Sam Walton or Bill Gates, a fake war that is even less popular than Viet Nam was in 1973/'74, and on and on. All of these things speak for themselves, and they speak volumes. We'll be paying for these follies for the rest of our lives, and for the rest of our grandchildren's lives.
And then there's Dubya's squashing of the Constitution and Civil Rights after we've worked so hard to get and keep these things, and every cemetery in the Nation is full of good, decent, selfless men and women who died defending those very things and the democratic principles that are the Bedrocks of our entire Nation.
Maybe it's not so much that any thinking/informed/coherent person embraces the democratic party. They just despise the republican party. Everybody gotta be someplace.