Biden will be squeezed from both sides – by reeling Republicans who may look to run the same playbook that stymied President Obama and Biden as they took over in the White House in 2009. But, he’ll also face pressure from his left flank.

The left will be looking for top progressives to land leading roles in Biden’s administration, and will be pushing hard to implement their agenda on the economy, social justice, civil rights and judicial reform, and on combating climate change.

Firebrand lawmakers on the left – such as Rep. Alexandria Ocasio-Cortez of New York – kept the peace during the general election, but with the Democrats’ common foe now defeated – infighting may soon commence, with the left scrutinizing every move by a politician firmly planted in the center-left of the party.

Also hovering over Biden: questions over his durability and whether he’ll run for re-election in four years. The last thing the president-elect needs at the onset of his tenure in the White House is to be collared with lame-duck status.

Biden hasn’t ruled out seeking a second term. Asked in August if he was open to running for re-election, he said “absolutely,” in an interview with ABC News.