[jkaplowitz]

Congress failing to block a rule by passing a CRA resolution is very different from Congress approving of the rule. For example, if the majority in the House supports a rule but the majority in the Senate does not (or vice versa), neither an explicit approval action nor an CRA blocking resolution can be passed.

[Cody-99]

Not really. If congress writes the laws intending the responsible agency to resolve ambiguities (which they do in just about every case) and doesn't object via CRA I don't see how that isn't an explicit approval.

[jkaplowitz]

It’s incorrect to assume that Congress knows and intends every ambiguity they create and that they can foresee and approve of all the interpretations an agency might reasonably come up with for each such ambiguity.

Even in those cases where they recognize an ambiguity they create and where the agency’s interpretation is within a scope that Congress approvingly foresaw, that’s at most an implicit pre-approval of the agency’s regulation, not an explicit approval of the regulation in the sense that defeating a CRA resolution would be.

Far more importantly, most CRA resolutions attempted to date have not occurred in the same Congress as the one that passed the authorizing legislation for the regulation. There is no reason at all to assume that the Congress attempting the CRA resolution holds the same view on the relevant agency interpretation as the one that passed the authorizing legislation, whether that view is approval or disapproval.