Glad you liked the post, Mike. The authors of the article I discuss get their data on race and Presidential elections from exit polls, including those summarized here. 

I’m not quite sure what point you’re trying to make about Lincoln and MLK. The political realignment I discuss in this post developed largely in the wake of the Civil Rights Movement and King’s assassination. 

I’m also puzzled by your reference to the Democratic Party’s “divide-by-race obsession,” given the widely-understood manner in which the Republican Party has used the so-called “Southern strategy”>/a> to achieve the racially polarized electoral results discussed above. 

BTW, you said, “no Democratic presidential candidate has won a majority of the white vote since LBJ himself was elected in 1964.”  Was this based on exit polls?  How do you know the “race” of the voters?

As far as the next transition goes (character over skin color), we all
are waiting for the Democratic Party to finally drop their
divide-by-race-obsession and join us on the other side.