I give it 1 year, possibly 2 before they have to kick him out
Therein lies the problem. The primary races are where each party chooses their candidates for the general election. There are primaries for president, which gets all the attention, and also for House and Senate races as well as all the other offices. In any voting district, if there is more than one candidate for the same position from the same party, the primary picks the one who ends up on the ballot for the general election. Once each party has picked their candidate in the primary, the candidate runs against the other party's candidate and any independents in the general election. So, Kamala ended up with less than 2% support of the Democrats who voted. Bernie was the leader but the Democrat party knew that since he was an avowed Socialist, he had no chance of beating Trump so they talked him into quitting early and none of the other candidates could beat Biden so by default, Biden won the primary. Sadly, if people actually vote for Biden and he gets elected, we will end up with a president that less than 1% of the population voted for (assuming that Democrats and Republicans are roughly 40-40 with 20 undecided.
He said today that he is Kamala's running mate, instead of the other way around.
That really was Biden being funny. While standing in front of a huge sign that said "Kamala", he introduced himself as Jill's husband and Kamala's running mate and then said - "and you think I'm joking". So, he knows what's going on when he's lucid. Biden makes jokes the way that Trump does and this was one of them. Except, that it was something that he actually shouldn't have admitted although it isn't likely that anyone on the left actually picked up on it.