Little known fact.
Yes Jefferson owned slaves, but he freed all of them. They stayed on his plantation willingly. Slavery was a very dark part of American History. But Jefferson did the best he could under the circumstances.
Yes the declaration of Liberty and Justice for all turns out to mean Liberty and Justice for and white males who owned property. It would take a Civil War some 80 nearly 90 years later (after Jefferson's statement about Justice and Liberty) to resolve the slavery question with a civil war. But you cannot dictate correct behavior no matter who you are or what your position in government. In a democratic society, the people must agree to be ruled by the constitution that is put in place.
Jefferson was not a hypocrite. He was a man caught and bound by the rules and laws of his time. He led by example. He freed those he could.
As for King, [if you are talking about Martin Luther King], he may have applauded both words and actions for he undoubted knew about the the freedom granted Jefferson's slaves.