20RP12 triangulates from his libertarian roots during the primaries to get the Republican nomination. In order to appease the base, he picks little-known Supersonic. The move excites said base, but costs 20RP12 the support of moderates and a number of independents.
Fortunately for him, that lost support stays home rather than supporting his Democratic opponent. JulioMadrid rides a wave of anti-establishment, anti-right wing backlash and becomes another successful dark horse Democratic nominee. He picks Alfred, a freshman politician of more orthodox views in hopes of shoring up the blue dog base, but the geographically unbalanced ticket does nothing to help him and "mainstream" media easily paints Julio as an "out-of-touch liberal elitist."
Turnout on election day is near historic lows. In the end, the Democrats pull of a victory, but a very narrow one; a number of their key victories are merely a percentage point away from flipping.