Republicans in Congress can work with Trump and pass legislation on their own terms and their own schedule. Rules do not work that way. Rule-making is generally a slow process. And the same process must be followed whether the agency is adding a new rule, amending an existing rule, or repealing a rule.
#TheResistance can use the rule-making process to the advantage of the Movement to slow the adoption of new rules, amendments, and even repeal of existing rules. If done well, changes anathema to progressive values could possibly be blocked until 2018.
Understanding the Rule-making Process
The Administrative Procedures Act (APA)
How to Organize, Coordinate, and Work Together