Doing the right thing is usually divisive.
Presumably any state that had slave and joined the North would be allowed to keep its slaves to the detriment of the white workers.
Not "presumably" - according to the letter of the law they would. The Emancipation Proclamation had no effect on the slaveholders of Kentucky, Missouri, Delaware, Maryland or Washington DC.
Naturally the abolitionists wouldn't accept such an idea either.
Some abolitionists thought the EC wasn't good enough. The vast majority recognized it as an important step forward.
Lincoln's own attitude toward blacks demonstrates that the Proclamation wasn't based upon distaste for slavery as much as a war time measure against the South.
(1) Lincoln's "attitude toward blacks" changed over time. His attitudes and ideas in 1834 were not identical with his attitudes and ideas in 1864. Like most people, he learned quite a bit over the course of 30 years.
(2) Lincoln always had a distaste for slavery. He was one of the original freesoilers - one didn't need to have an enlightened view of black people in the 1830s to realize that slavery was a really, really bad idea.
(3) The EC was clearly a calculated move, but a calculated move that Lincoln also beleived was morally right. Lincoln quite openly told abolitionists that his main goal was perserving the Union and that he would agree to either maintaining slavery or abolishing slavery as long as the Union survived.
And Lincoln knew that once it was issued, the EC would prevent the UK and therefore France from entering the war on the side of the Confederacy.
Further given his treatment of any that spoke against his policies shows that divisions in the North cannot all be laid at the feet of any one group.
What "treatment" was that? Be specific.
And the draft riots show there was a full measure of racism in the North too
Of course there was.
That is pure nonsense. Lincoln's 'distaste' for slavery was long standing and very well documented. You are correct however that the EP was issued (and could only be issued) as a "war time measure."
As President, Lincoln had no authority to end slavery. It could only be ended by individual states themselves or via Constitutional Amendment. But as Commander-in-Chief, Lincoln did have the power to end it as a military necessity in areas in rebellion. That is what the EP did.
No overlooking Lincoln’s political wisdom which you pointed out. Lincoln’s goal was to preserve the Union. That was not a task for the faint of heart and only a man of his transcendent greatness could have accomplished it.
It is no secret that slaves were only freed in the territories not under control of the federal government.
Lincoln’s hatred of slavery was so well known that the Slavers revolted when he was elected. That is no secret either.
The Draft rioters were Democrats. Largely the criminal gangs which plagued decent New Yorkers during the 1800s almost all were linked to Tammanney Hall.