2020:Kamala Harris was nominated in a competitive Democratic primary field. A Democratic northeastern candidate became VP (Let's say Tim Ryan from Ohio). Donald J. Trump is still quite controversial but the global political climate favours him. The second part of his first term will turn out to not be so bad after all, or at least he will have convinced and won over some moderates and independents, and his approval ratings will go up to 50 / 50, and will especially have increased in the Rust Belt, partly because of weak Democratic opposition and Democrats not being able to find a correct strategy to win WWC voters back who shift more & more to the Republicans compared to past decades. Democrats keep the house (narrowly) and make gains in the senate, but Republicans keep a narrow majority in the senate (because of gains in 2018). The country is still divided.
2024: Vice-President Pence is nominated after a contested primary against a more moderate Republican, an alt-right figure and a different person who declares himself as a Trumpist: all of them claim the legacy of Trump (except for the moderate establishment Republican and some candidates who were already eliminated in an earlier stage). Pence mainly won because of name recognition and as serving for VP. Trump leaves office relatively popular (although still disliked among liberals and democrats, but increasingly getting popular among independents and moderates). Pence can't entirely profit from this, as the Trump effect wears out and as he is prone to making gaffes.
The Democrats have nominated Sherrod Brown in order to win the Northeast back. The senator's third term would have finished, and he would have been an ideal fit. He had as well a very contested primary against Cory Booker and Julian Castro who did split the minority vote. Brown decides to pick Castro as his VP in order to unite the base, and reach out to Hispanic voters and the Southwest as well. Castro - who turned out to have a lot of charisma. The race seems to be a closely contested one, but contrary to the last two presidential elections, this time the polls seems to underestimate the Democrats and they expand their leads in the last month running up to the election, and take back by the White House by sweeping back the Rust Belt, and flipping Arizona. Texas and Georgia end up being close, but still choosing Pence. Florida is also still close.
2028:Sherrod Brown turns out to be a very popular and good president, and Julian Castro is popular as vice president as well. They turn out to have united the Sanders wing as the establishment / moderates as well. Brown seems to have convinced a lot of Trumpists because of his progressive but also economically populist and nationalist platform. The GOP is a bit in a crisis over it's future, and during the primaries Ted Cruz is nominated as the candidate. This election might have some parallels with the 1964 presidential election, and is the last one before a major re-alignment will occur. Cruz just doesn't seem to make ground and loses quite decisively against a popular incumbent, while losing his home state as well. Kansas, Missouri and Montana narrowly went for Cruz.
EDIT: I've deleted 2032 - 2040. I need more time about this, and i struggle with how the Republicans will re-align. I'll do 2032 - ... later on (and probably do so more elections after 2040)
2020: P. Donald Trump VP. Mike Pence / S Kamala Harris R Tim Ryan
2024: S Sherrod Brown S Julian Castro / VP Mike Pence S Susana Martinez
2028: P Sherrod Brown VP Julian Castro / Former S Ted Cruz S Tim Scott
Golden rule: Never appoint a VP with the name Tim because it's a sign you'll lose
