Assuming these are true (of which you've provided no evidence) does it surprise you that a man who was raised in a racist society would use racist terms to describe black Americans? Abraham Lincoln didn't even think blacks and whites could live together for the majority of his life, and wanted to deport blacks back to Africa as late as 1862.
Actually, he wanted to establish a voluntary colonization program. Colonization was a very common position among abolitionists.
Lyndon Johnson was a racist man, like nearly all white Southerners (in both parties; Southern Republicans were anti-CRA too). Being a racist doesn't mean you can't be a civil rights supporter either. Lyndon Johnson also said this:
There were plenty of Southern Republicans who were pro-civil rights, like Charles Pickering and Frank M. Johnson. As a Senator, LBJ fought to block the 1957 Civil Rights Act and made it nothing but a nominal bill. JFK also opposed that bill.
While granted that Frank M. Johnson was always pro-civil rights, Charles Pickering was not, at least at first. In 1964, he said that "the people of Mississippi were heaped with humiliation and embarrassment at the Democratic Convention" in Atlantic City, New Jersey, after the national party seated two civil rights activists from the Mississippi Freedom Democratic Party with the all-white delegation that he had strongly supported.