Based on the information provided, the best conclusion is: The Johnson administration was more liberal than the Nixon administration.
This conclusion can be drawn from the context of the policies mentioned. The Johnson Administration's initiatives such as the Voting Rights Act and the Great Society were focused on civil rights and social welfare, which are typically associated with liberal policies. In contrast, Nixon’s administration, while it did establish the Environmental Protection Agency, also employed strategies such as the Southern Strategy, which aimed to gain political support from the South by appealing to racial tensions, a move often viewed as more conservative. Therefore, the overarching political ideologies that characterized both administrations suggest a more liberal approach under Johnson compared to Nixon.