The problem is that we're looking at the 1860 election, and Lincoln as a war leader, from the persepctive of 2007, not what they knew at the time. Between 1840 and 1853 the United States grew in size tremendously-- from Mexico to the south and west, and "from" Britain to the north. After 1867 the United Staes didn't acquire any more territory. (Seward's Folly, remember?) The South expected to acquire a whole lot more territory in the Caribbean, Central America and Mexico, much of which would be good land for slavery. If slavery was on the way out in 1860, you could not find any evidence for this in the writings of Toombs, Rhett and Yancey, to name some prominent Southerners who wrote on the subject. Lincoln took office already faced with secession-- not as a result of his policies toward slavery as such, but his policy on whether a territory could restrict slavery before becoming a state. He believed in the Union-- and believed that since the Union existed, that he had no power to interfere with slavery where it existed. To me, he did his best in a bad situation. I admire him greatly, if you can't tell.
And the quote about Grant as I remember it is "I can't spare the man. He fights." (this at a time when Grant had tried seven times to caputre Vicksburg and failed each time)