Hillary and Biden would probably swap campaigns, with Biden running in 2016 (largely because Hillary isn't going to challenge an incumbent President), and narrowly losing to Romney, and Hillary running in 2020, and narrowly beating Paul Ryan, largely because of COVID sinking Ryan's chances as a representative of the incumbent administration.
Doubt Biden would run in 2016, a big reason he stayed out was his son's death from brain cancer in 2015. Not to mention an Obama loss would repudiate his administration, and the 2012 election post-mortem would basically be to hand the party to Clinton.
The economy crashes again in 2011 as a contagion effect from a Greek default and exit from the Eurozone, there's a big Islamic terrorist attack in 2012, and Osama bin Laden escapes Operation Neptune Spear. A Romney/Rubio ticket beats Obama. In 2016, Clinton overcorrects for Obama's perceived dovishness and social liberalism and takes a lot more damage in the race with Sanders, then comparisons between Romney's plan for energy independence and Clinton's plan for a no-fly zone in Syria destroy her campaign. Economic recovery ends with the outbreak of the Iran War in 2018, and things go to hell in a handbasket with COVID in 2020. Vice President Rubio just barely fights off a populist challenger, while Democrats are rudderless and Sanders pulls through.
Vice President Marco Rubio (R-FL) / Senator Rob Portman (R-OH)
Senator Bernie Sanders (D-VT) / Senator Cory Booker (D-NJ) ✓