There are rumors that President Trump will run for Congress in 2022, and that if there's a "red wave", he could become the Speaker of the House. He hasn't made any such announcement, but it's possible that he will in the future. When asked about it, Matt Gaetz smiled and said that he liked the idea.

I have a theory that if the rumor is true, this could be how he returns to the White House. Becoming Speaker of the House would put him first in line for the position of Acting President if Joe Biden and Kamala Harris were to both be ousted.

It seems obvious at this point that the reason that Biden hasn't been ousted through the 25th Amendment despite his blatantly obvious dementia is that the Democrats want to wait until he has served at least two years and one day (January 21, 2023) to get rid of him, so that his successor would be able to technically serve less than half a term and thus be able to run for two more (serving a total of ten years, minus a day or two).

They presumably intended in the beginning to replace him with Kamala Harris, and that may still be their plan. However, considering the rumors of Harris being on outs with Biden and possibly others within the Democrat Party, it's possible that they now want to get rid of both Biden and Harris and put in Nancy Pelosi (who is currently first in line if both Biden and Harris are ousted). Or maybe President Pelosi was plan A from the beginning.

On January 12, President Trump said:

The 25th Amendment is of zero risk to me, but will come back to haunt Joe Biden and the Biden administration. As the expression goes, be careful what you wish for.

Notice that he says that the 25th Amendment "will" (not "might" or "may") come back to haunt not only Biden himself, but the entire Biden administration (which presumably would include Kamala Harris).

Could it be that this was a hint that by the time the Democrats are ready to oust Biden through the 25th Amendment, Nancy Pelosi will be replaced by Speaker of the House Trump, and something will happen to remove Harris from the presidency as well, ending the Biden administration and bringing back the Trump administration for slightly less than two years, allowing for a 2024 presidential run and another four-year term?