The Dems will get two years (with a hostile President) and be blamed for not fixing things fast enough in 2028.
If history is any example we already know congress won't do much unless it involves spending money. We saw that with the republicans expanding ICE funding instead of making careful country wide immigration reforms in collaboration with state governments who are needed for proper enforcement. Most likely if/when the democrats win we'll see them fund a new flashy anti-corruption agency, which gets added on top of the other 400+ federal agencies who already have multiple overlapping responsibilities.
And that doesn't work all that well if SCOTUS and POTUS work to just nullify said policy, as they did with things like the Voting Rights Act, the Clean Air Act, etc.
See, for example, Biden's attempt to forgive student loans (despite legislation permitting it) versus Trump's green light to try and wipe out the entire (Congressionally established) agency.
Best way to avoid this is having a competent congress, one that actually responds to public concerns so it's not forced upon the president. Which is always the root cause of all of this bad policy from the WH getting shut down by courts or risky incomplete policy being ignored by the courts for the greater good (like abortion rights never becoming a hard law through congress).