Nixon had a heavily Democrat House and Senate. Exactly how would you propose he could have turned back the “Great Society?” Do not blame anyone but LBJ for that and the $Trillions of debt it has incurred ever since.
EPA was coming one way or the other; he started it to make it less intrusive tho it has become that. I don’t think you fully understand the impact of the then-Democrat controlled political picture. They controlled the legislature, and the bureaucracies (and still control the latter).
Note that Reagan, the “ultimate conservative,” didn’t undo the Department of Education put in by Carter.