Today I saw that NBC News has pulled out of the vault a rare interview with Dr. King recorded in 1967. He stated that his dream has turned into a nightmare.
His vision of civil rights for all Americans was probably still strong but he found other issues of great concern. poverty and Vietnam War were those issues. Just before his assassination he was definitely setting his sights on poverty or otherwise issues of economic justice.
Also noted his position as a Civil Rights leader was no longer unchallenged. Non-violence was not the preferred method of many young Civil Rights leaders who were emerging. Increasingly "Black Power" became the slogan of choice.