What will it have to take to have a 500+ EV landslide occur today?

[Statilius the Epicurean]

Even more important than partisan sorting is the geographical sorting of the parties. In California there are over 3.5 million more registered Democrats than Republicans, that's asking for a hell of a turnaround for the GOP to win it and get over 500 EVs.

I could imagine a scenario like this: Booker wins a contentious Democratic primary in 2020, beating out Warren and the progressive wing of the party in a close race. In the general Booker beats Trump handily in a 300+ EV victory. In office, Israel and Iran come into conflict and US troops are sent to occupy Iranian ports, oil prices spiral and a global depression hits. To head off a debt crisis President Booker is forced into a grand bargain with Congressional Republicans delivering swinging cuts to Medicare and Social Security. Incensed at all this, progressives unite under an anti-war primary challenge by Gabbard, who withdraws to mount a third party challenge after narrowly losing the Iowa and New Hampshire primaries, citing the "rigged" process. With the Democratic coalition cleaved in two, GOP nominee Tom Cotton sweeps to a 500+ EV victory on an "end the Democrat depression, fight with honour" platform in a 53/24/21 victory.