They could become Joe Biden's vice president

In this case, age plays a role in two ways. Should Joe Biden become President of the United States, it is speculated that, due to his advanced age, he will only serve a term of office and then hand over the baton to the Vice President.

Then the sum of age also plays a role.

- A good rule of thumb is that you should make sure that you are 150 years old together and that means that he will not choose anyone over 70 years, says Andreas Utterström.

Here is Utterström's list of the most likely candidates:

- What speaks for Kamala Harris is that she is a very ambitious person. She is in her 50s, which is basically a teenager in these contexts. However, she seems to have many enemies. The big question mark is how well she and Joe Biden get along personally, because that is the most important thing.

- Elizabeth Warren is over 70 years old, which speaks against her. What also speaks against her is that she is politically much more to the left than Biden does. What speaks for itself is that it could unite the party.

- Susan Rice was a national security adviser under Barack Obama. She has been an official and has never been elected, which speaks against her. What speaks for her is that she has a very solid knowledge and is very respected. I think it can be difficult for her precisely because she never ran in an election.

- Stacey Abrams is a "rising star" in the party but she has no experience from Washington. She definitely has the future ahead of her. If you compare it with sports, she has grown out of the junior team, but the question is whether she is ready for the senior league.

Karen Bass is the leader of the African-American group in Congress, the US Congress. She has a lot of power but most Americans do not know who she is. There are many who lobby for her behind the scenes.