So do I, but the Declaration did not form a government, and Lincoln did not take an oath to uphold the Declaration, he took an oath to uphold the Constitution.
There is a higher law than the Constitution. Lincoln said that all his political ideas sprang from the D of I. He was not in favor of forcing anyone out of the country -- especially after they helped save the Union.
"Why should they give their lives for us, with full notice of our purpose to betray them?" he retorted."Drive back to the support of the rebellion the physical force which the colored people now give, and promise us, and neither the present, or any incoming administration can save the Union." To others he said it even more emphatically. "This is not a question of sentiment or taste, but one of physical force which may be measured and estimated. Keep it and you can save the Union. Throw it away, and the Union goes with it."
There was no way Lincoln was going to betray the blacks, as you seemed to imply.
Walt