Have him solve the energy crisis. No three mile island, malaise speech gets followed up not by cluelessly firing his advisors, but by a massive infrastructure investment program building reactors, renewables, trains/transit, and walkable cities, somehow in a way that doesn't create inflation...
The biggest thing the Soviets would do about global warming, once concern over it became widespread, would be to serve as an alternative diplomatic pole for the global negotiations. The defining feature of climate negotiations since Kyoto has been that the world's sole superpower refuses to...
A grandiose Roman Empire would also benefit from having a much stronger naval frontier tradition. A Rome that has more self-sustaining trade and naval strength in the border seas (North Sea, maybe Baltic, Black Sea, greater Arabian Sea) would be in a much stronger position to expand and defend...
Better management of the Aral Sea, and central asian irrigation generally. Better soil management and less ambitious export targets could help. The great northern river reversal would in theory enable tremendous long term economic potential, but would be very costly and likely produce all...
Going back a little earlier, Eleanor Roosevelt could have a shot. She's a plausible VP candidate from 1940-1952; if Franklin declines a third or fourth term, or by a democrat after he dies who wants to run on the New Deal legacy.
Expanded Amtrak and electrified transit projects, supported Navy-operated nuclear reactors. He needed a plan to prevent an oil crisis, and he never produced one. He cut Amtrak routes as a cost saving measure just in time for the 2nd oil shock, when Amtrak ridership jumped, but didn't have the...
A revolution, invasion, or some other defeat of the monarchy in the home islands could lead that way. It'd probably help to have the respective Windsors marry into the local aristocracy, which could be done in the Raj as soon as necessary post-Victoria.
Russia sent ships to deter British intervention, and to get them free to manuever in case Britain or France intervened in Poland. They had a decent morale impact, and may have fought a confederate raider off from San Fransisco.
Republican obstruction would still happen, but if McConnell loses to a Democrat (as opposed to another Republican in the primary), it'd have a significant impact on Republicans' ability to obstruct before the 2010 midterms. Democrats technically had a filibuster-proof majority, but only for...
Not sure how to make it happen, perhaps different Obama rhetoric around guns and coal? Avoiding "clinging to guns and religion" might help there. Earlier and greater evidence linking his wife to cocaine and/or corruption could work.
Without McConnell in the caucus the total obstruction line...
For reconstruction to succeed, the freed slaves and their white allies will need to be able support themselves economically and defend themselves militarily. The former will generally require land reform; if freed slaves actually got 40 acres and a mule, you wouldn't have sharecropping, radical...
Conceivably you could have one as far back as Reconstruction. There were a reasonable number of Muslim slaves taken to the Americas, and a few who kept the faith going even after a couple generations in bondage. Have a little more of that survive, and/or a greater emphasis on reengaging with...