Governor Antonio of New York easily wins the Democratic primaries due to a fractured center. To appease moderate voters turned off by his solid left-wing views, he chooses Senator Vosem of Illinois, who abandoned the Republican party the previous year due to it drifting to the fringe on social issues.
Meanwhile, the insurgent campaign of Representative 20RP12 runs slightly behind the more establishment Cathcon the entire primary season, but not far enough to avoid a brokered convention. About thirty delegates who were pledged to Cathcon switch to 20RP12 on the second ballot, giving him the nomination, whereupon he picks Cathcon for VP to try to hold the party together.
20RP12 runs up the totals across the Mountain West, but does not do so well in the South. The Antonio/Vosem ticket wins in a near-landslide in November.
Antonio (D - NY) / Vosem (I - IL) - 386 EV, 52% PV
20RP12 (R - PA) / Cathcon (R - MI) - 152 EV, 47% PV