The Democrats in their infinite wisdom in 1864 ran a pro war candidate, McClellan, for President and teamed him up with a rabid copperheed VP. His name escapes me right now.
Nevertheless, if Lincoln were so universally hated, it shouldn't have mattered. On paper, McClellan was a strong candidate. It is doubtful that the Democrats actually had someone who would have beaten Lincoln in 1864.
BTW, George Pendleton was the Democrat VP candidate. He is very forgettable.