Actually, it doesn't. She serves as "Acting President" until such time as the disability is resolved.
The question is whether she also retains the office of Vice President while serving as Acting President. I would think so. This is an important distinction.
If Biden resigns and Harris becomes President, the VP slot becomes vacant until she nominates a replacement and both chambers of Congress confirm the nominee. I can see Republicans in the House rejecting her nominees to keep the office vacant until the end of her term. This serves two purposes:
- If something should happen to Harris, then Speaker Mike Johnson will become President.
- Without a Vice President there is no tie-breaking vote in the Senate. With the Democrats holding a 51-49 majority (actually 47-49 with four independents caucusing with the Democrats), all it takes is one Democrat to side with Republican to stop a bill from passing (hello Joe Manchin).
If they go the 25th amendment route an Harris is both Vice President and Acting President, they get the best of both worlds, but Harris won't get her robot at the Magic Kingdom in Disney World. Acting Presidents aren't Presidents.
-PJ