There is this speculation, and not just by conservatards, that Biden has signaled me may not run for a second term. There is a lot that will happen in the next four years, so it's just really hard to speculate accurately at this time what will happen as the 2024 election cycle starts to heat up.
One very interesting scenario could be very, very potent when 2024 gets here. IF things are generally going well for Dems, and IF Biden really doesn't feel up for a second term, and IF Harris has demonstrated the chops to sit in the Big Chair ... IF All That ... THEN
Biden could resign around January or March 2024, let Harris take the presidency, select a VP and effectively run for her first term to follow Biden. One of several moving parts here is that if Harris serves too much time of one of Biden's terms, then she becomes ineligible to run for two full terms as president. I think she has to serve less than one year to be eligible to then run for two full four year terms, but with a little research that detail can be easily clarified.
Anyway, this would be a way to put Harris in a very strong position to win the 2024 election.
Alternate scenario: Biden serves his second term and does the same thing as described above, but resigns in Jan or March 2028 to let Harris then run for two terms.
Yeah, this makes conservatards shit massive piles of bricks. It's a very real strategy and could really stack the deck for Harris if all other factors are fairly normal.