Quite the interesting alternate timeline that would be. Supposing the Democrats introduce such a law in 2021-2023:
GOP takes the House, and is seated in January 2023.
GOP uses Trump’s evidence against Biden. Biden, due to the new law, is impeached in February.
The GOP generates some evidence against Kamala as well shortly after she appoints a new vice president. Kamala is kicked out in favor of the new vice president.
After lots of revolving door action, the holder of the Presidency eventually stabilizes as a very submissive moderate neither side takes much offense to. Sorta like Mike Johnson in a way, but the other way around.
The importance of the 2024 election has a far greater dependence on the legislative branch. If either house of Congress has an opposing party, the President won’t be around for long unless they do what Congress says. Even if Trump wins the election in this timeline, he’s screwed if the Democrats keep/retain the House or the Senate.
And even if Trump achieves a trifecta in 2024, allowing him to stay in power, he’s doomed if the Democrats take either house in the midterms of 2026.
Quite the interesting alternate timeline that would be. Supposing the Democrats introduce such a law in 2021-2023: