Yes, Lincoln's handwriting is messy, but you are grasping at straws in your attempt to reject the fact that Lincoln wrote those words. Lincoln did in fact write those words.
If you can't read it, I gave you the link to the source, and you can just hit the button that says "Transcript."
Do a text search on the Transcript, and you will find the relevant text.
After that, you will have to argue that people entrusted with keeping some of Lincolns documents are liars or something.
If you are an honest man, you will come to the conclusion that in 1848 Lincoln believed people had a right to secede from governments that they believed didn't suit their interests, but by 1861 he had decided to claim that he didn't believe this.
Please tell me what Lincoln did, NOT in 1848, but during the conduct of what we seem to dispute as the Civil War even Ken Burns acknowledges. Go away