Technically, they can actually do the work of Congress and the Senate which should stop the orange pedophile from basically doing whatever he wants whether he has legal power to do so or not (as he has been doing in the last 2 years)
They can also release the Epstein Files or start jailing people blocking the release... as well as running actual investigations, hopefully leading to criminal investigations, for all the naked corruption the orange menace regime has committed.
Finally, they can impeach and maybe even remove the child rapist pressy from office (not sure about this one, they may need a bigger majority for that).
In reality, I am not sure if they will do any but the first one but I am not the most optimistic person out there