Civil War
If democrats held control of Congress and the WhiteHouse I'm afraid there would be no limit, republicans couldn't give them everything they wanted, so democrats would try to take it all and pass tyrannical socialism into law, I fear it could provoke the worst possible outcome.
Harris/Walz are too radical, they are not moderates and half this nation isn't going to sit still for forced authoritarian socialism, not in my opinion.
That said I don't think democrats will win all of Congress and the WhiteHouse, but you never know, our grand experiment is almost 250 years old, young voters today didn't learn the history we did in school, they don't know why our Constitution is so important.