Let it be known that Mr. House got beaten in the post-apocalyptic space race by a bunch of religious ghouls.
With help from everyone's resident favorite Courier, no less. So House's new star employee helped others beat him in the Space Race.
Also, I came across a great realization: Caesar's a fucking idiot. No, it's not because the NCR is correct, the NCR in-game is horrible. But Caesar could have gotten what he wanted if he simply offered a hand of peace with the NCR instead of fighting them.
Instead of spending money and blood trying to conquer the East, he could have just posed as an ally of the NCR. House doesn't like the NCR's government, his own government is autocratic as fuck, but he's not above breaking bread with them in order to gain some minimal advantage. Caesar could have done the same.
Edward Sallow could have used his knowledge of the NCR, especially his experience as a former citizen, to utterly cuck the government and slowly turn its elites over to his side. He could have offered a treaty of friendship to the NCR, having his bannermen go up to the NCR and say that "the great and mighty Caesar wishes to give greetings of good will to the land of his forefathers" and that Legion territory is open for NCR businesses, landowners, and merchant caravans to do business with. Have Legion troops guard NCR traders and corporate businessmen as they travel and do business in Legion territory in exchange for the NCR's tolerance of the Legion's use of slaves.
While some "DEMOCRACY GOOD" people in the NCR would obviously protest at the Legion's use of slaves, if Caesar gets enough of the NCR's rich folk to see him in a positive light, they can get the NCR to tolerate Caesar's use of slaves, and Caesar can even excuse it as his actions towards "barbarian tribes" while the the "civilized" civilian communities in Legion turf are barely accosted by the Legion outside of the odd request. Caesar can pose himself as the great hero of the NCR populace, since he came from the NCR, he organized tribes into a real army, conquering a large chunk of the barbarian wastelands and bringing them into the light of civilization. With all the rich people in the NCR eating out of his pocket, Caesar can easily run for election as the new NCR president, and with the NCR's elites backing him, winning an election will be child's play.
Once he becomes president, Caesar can then step up the NCR's militarization and transformation into a military dictatorship, stating that stability and security will ensure prosperity and peace, not to mention greater profits for the rich folk of the NCR and their businesses. In a few decades, both the NCR and Legion turf will end up becoming Caesar's new western American Empire; and with a robust bureaucracy supported by efficient soldiers and administrators from the Legion, bolstered by capital from rich NCR citizens and the commonfolk who won't have to worry about stupid things like Deathclaw attacks and raider parties anymore, Caesar can get what he wanted in the first place, without firing a shot at the NCR.
But I suppose the NCR failing to protect his family gave Edward Sallow a bad impression of the NCR, and he chose war with them instead.