There is always the possibility that he would have, yet there are reasons as to why he would not have been to enthusiastic in supporting it too strongly. One of these reasons is that Lincoln supported joining the South and the North as fast as possible to make the Reconstruction after the Civil War more smooth and faster. If he openly supported the rights of the Black people the South would not have supported him as much as they would if he had not done so. This would go against what Lincoln wanted the United States to do to heal, somethign that Lincoln's vice president also shared with him.
<h2>Important differences - Unlike the other two, Charles I was not associated with any political Party, and had not "risen through the ranks" to become Leader. As a King, he achieved his position by heredity, and since no-one can choose their parents, this was used to justify the doctrine of "Divine Right" - God dedcides that a child shall be born into a Royal succession, and it is blasphemy to make any attempt to change this. Similarly, it was therefore the "will of God" that he should be succeeded by one of his children - the eldest son, in the English and Scottish tradition. In England, there was also the unusual situation that, as well as being Head of State, the King was also Head of a particular religious organization - the "Church of England" - which meant that he could not be expected to recognise any other form of Christianity. It was his enforcement of this which aroused resistance by such men as Cromwell, who was against any enofrced religon, and for "liberty of conscience". (This was why Cromwell subsequently also opposed Parliament when it attempted to enforce Presbyterianism,) There is perhaps case for seeing a similarity in Stalin, since "Marxist/Leninist Communism" was in fact a "religion", even though a godless one. There are virtually no comparisons with Hitler.</h2>