Not being up on my Lincoln history … did he indicate, as Obama is doing, that he would have been happy with second place? Did they even have such a thing as a state caucus back in the day?
What he did from after the 1858 Senatorial election to the Chicago convention in 1860 was to make it clear that the other candidates, Seward, Stanton, Cameron, and Bates, were first-rate men, and he would be happy to be everyone’s second choice in the event none of them could get the nomination. (They were first-rate men; all four of them served in Lincoln’s cabinet). Sure enough, no one won on the first ballot, or the second; Lincoln won on the third ballot.
I sometimes think the old smoke-filled room was a cleaner and more efficient process than this four-year pandering, but Lincoln and Stanton worked hard for that nomination for two years, so it wasn’t that much more efficient than the current primary system.