How did black people react to Abraham Lincoln as a presidential candidate?
First of all, it's important to note that at that time no Black people in the US could vote, and in the South the vast majority of Black people were slaves. We don't have very reliable information about their opinions, because leaders at that time didn't particularly care what they thought and didn't bother keeping track.
What we do know is that many Black community leaders were initially quite lukewarm about Abraham Lincoln; they disliked his willingness to compromise with leaders in the South and felt that he was not pushing hard enough for an immediate and total abolition of slavery. While he was in Congress, Lincoln had fought hard to ensure that no new states were made into slave states, but did very little to undermine slavery in the states that already had it. Many Black community leaders feared that he would behave the same way as President.
Lincoln also held many views that were progressive for his time, but we today would recognize as racist; for example, he was in favor of racial segregation and opposed interracial marriage. This no doubt was part of the reason many Black people were ambivalent about Lincoln.
Opinion in favor of Lincoln shifted quite dramatically after the Emancipation Proclamation; Black community leaders were overjoyed by his actions and many felt that they had previously misjudged him. Lincoln's popularity among Black communities surged at the end of the Civil War when all slaves were officially freed.