I like the template of a Democratic primary used earlier by Antonio for three like-minded posters, so I'll adopt the same one here. This time, Antonio is serving the role of New Deal progressive, Scott of the New Democrat, and Morgan of the left-libertarian.
In Iowa, all three candidates are competitive, but Antonio narrowly comes out on top. The real surprise is Morgan's second-place finish, which gives him enough momentum to upset favorite Scott in the granite state. Scott's campaign appears to be in trouble, but he manages to stay in the race with two decisive victories in South Carolina and Florida. At the end of January, the map looks like this:
On Super Tuesday, Scott's victories are confined to the south, while Antonio wins two states in the midwest, one in the northeast, and one in the west, garnering most of his support from the working class. In a disappointing day for the Morgan campaign, Morgan, who had been hoping for victories in Minnesota, Vermont, and Colorado, won just one of those contests. Despite speculation from the media, Morgan announced that he will stay in the race.
By the end of March, Scott seems to have the election wrapped up. It seems peculiar that a campaign which lost both of the major early states would be so far ahead, but the strategy adopted by Scott after his defeats explains his comeback: While Antonio and Morgan were busy trying to out-liberal each other, Antonio on economic policy and Morgan on social and foreign policy, more middle-of-the-road voters felt dissatisfied with the two major candidates. Recognizing this divide, Scott emphasized his more centrist and third way positions to gain the support of this left-out constituency. The strategy seems to have worked. Morgan officially withdraws from the race and throws his support behind Antonio. It's now up to him to stop this juggernaut which seems destined to capture the nomination.
Antonio puts up a commendable fight, but it's too late. The momentum is on Scott's side, and it's impossible to stop. Following Scott's victory in the New York primary, Antonio sees that continued resistance is futile, and he, too, withdraws. Here's the map following the New York primary:
And the map on the day of the convention: