Doing the math, as you suggest, reveals that President Lincoln simply did not have the votes necessary to abolish slavery peacefully through the U.S. constitution's amendment process.
If Lincoln wanted to abolish slavery, he would have to do it through force of arms - in other words, use violence to overthrow the pro-slavery U.S. constitution and to kill or imprison anyone who opposed.
For that he would need a pretext for war which he found in the Gulf of Tonkin incident. I meant to say the Fort Sumter incident.
Scroll up about 270 posts or so and you’ll see a couple of your fellow Lincoln opponents posting quote after quote about how Lincoln had no problem with slavery, hated black people, yadda, yadda, yadda. No problem with slavery, no liking for black people, no need to start a war to end it. So we’re back to wondering why Davis and his cohorts felt the need to start a war to defend slavery?