Some o' y'all are setting about things with a bad set of premises.
Regardless who started the war, Lincoln's "pretext" was that of preserving the Union; not any promise to end slavery. So if you want to know why Lincoln didn't immediately ban slavery, as soon as the balls started flying at Sumter, well there you go.
And I don't know where this mythical view of the Emancipation Proclamation began. Apparently, everyone seems to have learned in school that every slave was immediately freed, feted, and given 40 acres, a mule, and the key to the city. Then they find out the reality, and they feel they've been had. And maybe they have, but it wasn't by Lincoln.
That is kind of my point. You were probably side tracked by fistful saying that disagreeing with him makes us poorly educated.
No, I said ignorance on basic facts about the Emancipation Proclamation makes one poorly educated. Have any opinion you want; I'll just help you keep your facts straight.
So he can ignore some parts of the Constitution and enforce that with the military, and he can use force against Northern states for some things (draft riots), but using force against the Northern states for the ostensible point of the war was out of the question. Got it.
Last I checked, the abolitionist movement didn't have ultimate control of the Armies of the North.
Are those the same armies that were being run ragged by the South's early victories? Yeah, I'm sure they had plenty of spare time and resources to visit every slave-holder in Maryland, West Virginia, Kentucky, Missouri, New York, Massachusetts, or wherever you claimed all these slaves were. I'm sure all those people rioting against the draft would have welcomed that kind of federal assistance.
You'll notice I haven't defended Lincoln against the charge that he violated the Constitution in various ways. I'm not defending him on that level. I'm just pointing out that, whatever he might have liked to do, he wasn't Stalin. He didn't have that kind of power.
"Ostensible." I do not think that word means what you think it means. The ostensible purpose was to preserve the union. Now, I know you're not an idiot. Tell me what you think would have been more realistic for Lincoln, in the middle of a civil war - to put down a few riots up north, so he could hope to continue drafting soldiers, or to task his armies with ending Northern slavery, by his fiat?